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Friday, October 31, 2014

Doug's Domain

Doug Vetter, ATP/CFI

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Saturday, January 9, 2010

Visit with Technician

(Image: Technique to remove band clamp using straight pick)I dropped by the dealer earlier today to ask one of the technicians what kind of tool they use to fasten the special miniature band clamps used to secure the various connections in the windshield washer system. As I walked into the maintenance area I was pleasantly surprised to find my technician in his bay working. Since he's the lead in the shop he doesn't typically work weekends so I was naturally curious as to why he was spending one of his few days off screwing around with BMWs. It turned out he was doing a simple valve cover gasket replacement on his own car. I interrupted his work long enough to show him the crimp-type clamp and he kindly explained that contrary to their appearance the clamps are not designed to be permanently crimped like some of the other factory band clamps. He used a pair of diagonal cutters to pull the mating surfaces together until they snapped closed, then inserted a straight pick between the two mating surfaces and twisted it just enough to slide them sideways as required to open the clamp.

With that small task out of the way my attention naturally gravitated to a nearby bay in which two N52 blocks in various states of disassembly were located on engine stands. This was the first time I'd seen any BMW bottom end fully disassembled (close up, anyway) and took a few minutes to look around. When I asked what was wrong with the block my technician pointed out that BMW now uses a combination of aluminum and magnesium to construct their blocks to save weight. The magnesium wraps an inner core made of aluminum for compatibility with engine coolant. Problem is some of these engines have started to experience leaks in certain locations where the two metals meet. This led to a discussion on the current quality of BMW engines, to which my technician responded (paraphrased) that the E36 and E46 engines (M52 and M54) are more or less bullet proof due to their relative simplicity, but the newer N52 and N54 engines are showing signs of technology failures (like this manufacturing technology defect, turbo failures, etc.) that may affect the long term reliability of the engines. He was quick to point out that the block leak issue is very rare so it's likely but a blip in the data for BMW, but I took this as another sign that it sucks to be on the bleeding edge. I'll take the old and proven systems, thanks.

I also noticed that the new block had been fitted with new stock pistons equipped with sizeable valve reliefs. That prompted me to ask if the engine was still considered an "interference engine" and he responded in the affirmative. Lose that timing chain and you're going to bend valves. But fortunately -- at least for now -- BMW wisely continues to use a chain rather than a belt and the chains still appear to be designed to last the useful life of the engine (250K+ miles in the case of the M52 / M54). Of course, no one knows how long the new turbo motors will run as they haven't been around long enough. They may be able to meet the same lofty goals as the older engines in spite of BMW's "war on maintenance" (15K oil changes, "lifetime" fluids, etc.) but we won't know for many years.

Windshield Washer System Overhaul

I received the parts necessary to repair the leaking windshield washer jet this week and completed the repair today. I also managed to overhaul the system and through the installation of a new thermostatic switch, fluid pump and hose. The temperature was hovering in the 20's by the time I got out to the garage so I fired up the kerosene heater and got to work. I'm not sure if this work warrants a DIY but if it does I'll post it later. In the interim I'll simply point out what I learned.

(Image: Two heated washer nozzles disassembled)I determined that the leak in passenger side jet was due to metal corrosion rather than the heating elements. This jives with my earlier findings in that both nozzles appeared to melt the snow I placed over them. I did not discover the cause of the leak until I disassembled the old jets. The jet is in fact two pieces: an inner metal section to which the heating elements are connected and an external plastic shell that contains the part of the jet visible from the top of the hood including the two small jets that direct fluid to specific areas of the windshield. The inner section contains a single orifice that protrudes beyond its top face by about 1/8". This raised orifice fits into a corresponding cup of the same depth in the outer shell. Metal corrosion caused erosion of the face of the inner jet which resulted in a loose fit (thus a leak) between the interior jet and the external shell. Since the interface between the two sections is also responsible for heat transfer to the outer jets I now know why the leaking jet seemed to take longer to melt the snow.

While I didn't notice any operational problems with the driver's side jet I replaced it along with the leaking jet and noticed a much stronger and finer stream of washer fluid exiting the new jets. Substantial corrosion was found in the driver's side (working) jet but it obviously hadn't progressed as far as in the leaking jet. This means the driver's jet was likely to fail at some point in the near future so I made the right call to replace both jets. I imagine this is quite typical for these parts so in my opinion they should be replaced in pairs.

The fluid flows from the fluid pump through a single line to a Y fitting. The outputs of the Y fitting go to each jet. Since the washer fluid bottle and pump are on the right side of the car the passenger jet is connected through a small 4" section of hose and the driver's side is connected with a section that is slightly under three feet long. The piece I received with my parts order was 4 feet long so after cutting the necessary sections I was left with a spare piece about 8 inches long. I'm glad I replaced the hose because the old hose sections had hardened due to age and were not sealing well. I partially deformed the Y fitting during disassembly (the stressed area is recognized by its milky-white appearance in the picture) so I'm also glad I bought extras of that part as well.

Contrary to what the ETK (parts book) implied, no check valves are used in this system so I wasted a few dollars on those parts. Unfortunate, but unavoidable, as I had no idea whether the valves were hidden somewhere and wasn't about to disassemble everything earlier without the needed parts on hand. This isn't the first time this has happened and it won't be the last.

The new fluid pump is noticeably quieter than the original pump but that's about the only operational difference. I could have easily avoided replacement of the pump but I decided to file this under "preventative maintenance". I replaced the thermostatic switch for the same reason. Imagine spending $70+ on new nozzles only to have the switch fail and the nozzles freeze and crack. Replacement of the switch required removal of the passenger side protective panel under the bumper cover. No jacking of the front end was required to facilitiate access to it.

I found the special band clamps to be a bit temperamental. Some persuasion with the flat side of a pair of lineman's pliers were needed to bend the outer band down so it would grab onto the inner band sufficiently. I was careful doing this so as to not damage the brittle plastic fittings.

The last snafu of the day came when I attempted to replace the underhood insulation fasteners with the new parts: they didn't fit into the corresponding holes in the hood. I salvaged enough of the old fasteners to secure the insulation for the time being but I'm planning to bring the correct part to my local dealer and order a new set from them.

The job took about three hours of my day but that had a lot to do with my lack of familiarity with the various parts, my lack of interest in moving fast in the cold weather, and chatting with my brother. I estimate I could do the job again in an hour and a half. However, I think the job would be worth 2 hours of labor from the dealer simply because replacement of each item would likely add up to more than that due to book labor charges. So I'll call it two hours of labor saved or $256.

Mileage: 187050, Parts $157, Labor Saved: $256

Saturday, January 16, 2010

Aux Fan Runs Continuously (High Speed Relay Failure)

With the drive home completed for yet another day I stopped at the end of my driveway to pick up the mail. As I got out of the car I realized that the aux fan was running -- at high RPM, no less. Given that the outside air temperature was a balmy 26F, the coolant temperature gauge was pointing at the usual 12 o'clock position and I didn't have the air conditioning on (not out of the question in winter given that it is sometimes necessary for defogging the windshield, by the way), my instinct diagnosed the problem in an instant. One of the relays (likely the one that switches the fan to high speed) was fused closed. I'd read of this happening to other E36's and recalled that this failure mode would cause the fan to continue to run even with the ignition off (position 0), a condition decidedly unfriendly to the battery. Time to test that theory.

I pulled up to the house, turned off the key and opened the door with an odd sense of anticipation. Sure enough, the fan was still running. I got out, closed the door, and walked around to the front of the now dark vehicle with the fan eerily running with a mind of it's own. I stood there for a few moments contemplating the ghost in the machine before I set about to come up with a temporary workaround so I could sleep peacefully knowing I wouldn't come out to a dead battery the next morning.

I opened the hood and then pulled the cover off the fuse box. I began by tapping on what I believed was the low and high speed fan relays in an effort to free the contacts in case they needed a little persuasion. It had been a while since I'd messed with the low speed relay and while the fuses are labeled on the inside of the fuse box cover the relays are not so I wasn't sure I was hitting the right relays. When that didn't have any effect I decided to pull the 30A fuse for the aux fan (#41). Not surprisingly, with its supply of electrons cut off, the fan spun down to a halt. Problem solved -- for now.

While I waited for the wheat crust for my world-famous deep dish pizza recipe to rise I spent a half hour reading the schematics in the Bentley manual in an effort to further troubleshoot the problem. It didn't take me long to confirm that the aux fan receives power from the "hot at all times" bus through the high speed relay which in its depowered position delivers power to the normal speed relay. The normal speed relay contacts are normally open and break the path to ground (and thus keep the fan turned off) until the relay's coil is energized. And as it turns out, the coil of each relay is powered from the "hot in run and start" bus, so I quickly concluded that given how the fan was running in high speed with no power to either coil the high speed relay was faulty. The schematic also indicated I could have pulled the connectors associated with the refrigerant pressure switch or engine coolant temperature switch to rule those out but based on the symptoms I remained convinced that the relay was the cause.

The next morning I went out to the car and it started without any problems. I drove to the dealer to get some information from my technician and he was gracious enough to pull the wiring and fuse box layout diagrams for my specific model year from his archives and confirm the locations of the low and high speed relays. I pulled each relay and wrote down two part numbers to give to the parts department:

Normal Speed Relay (Yellow Case) - 61361389105
High Speed Relay (Purple Case) - 61361388911

While BMW is famous for supporting their cars far longer than most manufacturers, the one down side to maintaining a BMW older than 10 years or so is that the dealers tend to not stock parts for it and so it was in this case: I had to special order both relays. Cost for the high speed relay was $20 and the normal speed a mere $10 so given the critical nature of these parts, particularly in the upcoming summer months, I decided to replace both. They should be here in a few days. In the meantime, the car will run just fine with the aux fan fuse removed. All I have to do is treat this as an aux fan failure and keep the car moving if I decide to use the A/C to defog the windshield. I've never seen the aux fan run to address a coolant temperature problem in the winter so an overheat is of little concern.

Mileage: 187275, Parts: $40

Sunday, January 24, 2010

Replaced Aux Fan Relays

(Image: Normal and high speed aux fan relays disassembled)The parts required to fix the aux fan came in this week and finally managed to get to the dealer to pick them up. This morning just before I ran an errand I installed both the normal and high speed relays with no issues.

To test the system I reinstalled the 30A aux fan fuse and verified that the fan was not running with the key off. Then I started the engine, turned the HVAC temperature controls to full cold (60F), turned on the compressor (snowflake button) and verified that the fan was running (meaning, I had reconnected power to it successfully and the fan wasn't merely dead all the time now). I noticed the fan and compressor stayed off most of the time but that was likely because the 45F outside air temperature was below the HVAC setting. I could have pulled the coolant sensor connector and shorted the center pin to each of the other pins to prove the fan ran in both speeds but I figured that this was sufficient since I knew the fan worked -- I just needed to verify it no longer ran continuously.

As usual I conducted a post mortem on both relays (shown in the picture). I first inspected the high speed relay (purple body) and found the contacts in remarkably good shape, although they did have a bit of oxidation and one contact (used in the depowered state) showed a small amount of pitting. Overall, it looked like it was in relatively good shape so the reason for the failure is not obvious to me.

The normal speed relay was another story, however. With a mere 56K miles in service the contacts were in a condition similar to the last time I replaced it. I have always known that the normal speed relay takes most of the abuse and that explains why I specified a replacement interval for it in my maintenance schedule worksheet, but based on the condition of this relay I have decided to reduce the replacement interval from 72K to 54K to better reflect the wear pattern of this critical part. I don't like throwing money at the car even in the context of preventative maintenance but given the failure mode in this case I think it makes sense to be proactive.

Mileage: 187826

Sunday, March 7, 2010

Oil Service

The car had been due for an oil service for about two months but after several record snowfalls, prolonged subfreezing temperatures and a recent frontal sinus infection I just couldn't manage to do any work on the car. My usual oil service interval has averaged around 4500 miles, but this one stretched to 6123 miles.

Of course, my maintenance efforts were not the only activities to suffer recently. Pilots are required to conduct a certain amount of practice instrument flying every six months to maintain the ability to legally fly in clouds and my currency officially lapsed at the end of February. When I read the weather forecasts for this weekend I figured I'd do some flying on Saturday and work on the car Sunday. But alas, the dealer is not open on Sunday so I figured I'd stop there on the way to the airport and pick up an oil service kit.

Surprisingly I found my technician in his bay again, this time working on an associate's E46 M3 and using a brake paint kit to dress up the calipers in satin black. The paint is designed to be brushed on and based on the result of the first caliper it seemed to do the job reasonably well, though no matter how carefully the stuff is applied brush strokes in the finish are inevitable. I couldn't help but wonder what this stuff would look like thinned out and sprayed on through a HVLP gun. Done properly, of course, that would require removal of the calipers and this kit is clearly intended for those that would prefer to avoid that extra work. Nothing wrong with that...just a matter of preference. Would I paint my calipers? If I had the opportunity and tons of time and money to kill, perhaps. Likely? Not.

Today I completed the oil service after without any problems and took an oil sample I plan to send out shortly to verify the trend for higher lead discovered in the last sample. I'll post the results here when they come in. My usual undercarriage inspection revealed nothing other than a bit of ATF dripping off the bottom of the low pressure nipple on the power steering pump. I cleaned the area with a couple shots of brake cleaner so I could better track the state of the leak. I have plans to replace the power steering pump later this spring or early summer so if the leak persists I'll address it then.

Mileage: 189306, Parts $47

Monday, March 15, 2010

Oil Analysis Reveals Lead Wear Trend

(Image: Blackstone Labs Oil Analysis report from March 3, 2010)As you may recall, my previous oil analysis identified a slight rise in lead from an average of 4 PPM to 7. As the lab technician then indicated, and I agreed, that change did not warrant concern because it wasn't that far from the statistical average.

Yesterday I received the results of the sample taken last week and unfortunately it shows that lead has more than doubled to 18 PPM. The change has been identified by the lab technician as the likely start of a trend of increased bearing wear. The lab technician remarks that iron has also increased but that's only relative to the most recent samples. There seems to be some variability in the levels of iron over the previous five samples and the highest of 8PPM was found over 20K miles ago. As a result, I do not see iron at 10 PPM to be statistically significant.

I must admit that I am somewhat more skeptical of this sample than I would otherwise be because of the nearly 40% longer sampling interval. Some of the increase may very well be related to the increased time in service. The lab technician recommends additional changes with a shorter time in service and I plan to do that. I'm inclined to "reduce" the interval to 4500 miles so I can get the sample amounts back to a baseline to better identify the rate of change. However, doing the next change at 3000 miles would also serve to indicate the slope of the trend -- if the numbers are equal to or greater than this sample given half the time in service it might indicate the need to pull the engine sooner rather than later.

To better analyze the results and, I'll admit, do some daydreaming about what good could come of an engine rebuild I called Jim, owner of Metric Mechanic. He was kind enough to spend the better part of an hour over lunch this morning discussing the issue with me. I'll try to summarize it with a few points:

Of course, this is nothing more than the official start of the analysis and I intend to continue to use the vehicle without reservation. I'll likely schedule the next oil service and analysis in 3000 miles which translates into 2-3 months given my current driving habits. Stay tuned!

Mileage: 189777, Labor: $22

Sunday, April 4, 2010

Back to Summer Tires

The state of New Jersey recently experienced what I estimate to be the worst winter in my lifetime. Sure, we had a 3 foot blizzard in the late 70's that made the record books, but the frequency and severity of the Nor'Easters we experienced from December through February was just unbelievable. Fortunately, I managed to escape driving in most of it because of timing (two of the largest storms happened over the weekend and I was sick during one of them), but I did have to drive in the aftermath of all the storms and that's where the set of Dunlop Winter Sport M3 tires proved their worth. They practically glued the car to the road, even when compared to the otherwise excellent Michelin Pilot Sport A/S tires I'd run for several prior (albeit milder) winters. I'm sold on the performance of winter tires.

(Image: The E36 after it returns to summer rubber in April, 2010)With high temperatures now thankfully in the 60's and winter weather an increasingly distant memory I set about to swap the winter tires for the CSL reps wearing the Pilot Sport A/S Plus. That went off without a hitch yesterday. While the wheels were off I checked the brakes and estimated all four corners will be ready for replacement in another 6-8000 miles, which translates into mid-late summer given my current driving habits. I may try to combine that work with the suspension overhauls since I'll need to pull the brakes for that work anyway.

Sadly, the state of the finish on the CSLs is not good. The cheap finish has started to flake off in areas around the hub and rim of the wheel and the finish appears to be permanently impregnated with black particles apparently coming from the brakes. Needless to say, I clean my wheels once a week and it never happened to the stock wheels so I attribute this to the cheap finish typical of Asian manufacturers. I bought the wheels knowing I wasn't getting BMW quality but this indeed proves the old adage: you get what you pay for.

When I bought the CSLs I considered how they would look on the E36, but I bought them knowing they would eventually serve as an inexpensive winter wheel solution for the E46. As the finish has degraded to the point that I consider them "worthy" of winter duty, this will likely be the last year I use them on the E36. When the tires are spent I'm now planning to equip them with either another set of Pilot Sport A/S Plus or an appropriate winter tire (Dunlop does not make the Winter Sport M3 in 235/40 fitment, unfortunately) and keep them at the ready for the E46.

Then I'm planning to buy a set of 17" BMW M-Contour wheels (stock on the 1996-1999 M3). They match the unique lines and angles of the E36 and will be historically accurate for the car. And yea, they look sharp on the vehicle too. I'll then be able to wrap those tires with a high performance summer-only tire, very likely the Pilot Sport PS2. I once dismissed those tires due to cost but one perk of downsizing the wheels is that the PS2 is notably less expensive in 17" than the compromise all-season Pilot Sport A/S Plus in 18". The other perk is that they're lighter, which means less unsprung weight, less wear on the brakes, and better acceleration.

The question I haven't answered yet is whether I'll go with a staggered setup. The car definitely benefits from wider wheels and tires at all four corners, but the neutral handling of a square setup without the benefit of DSC also has a dark side too as I found out on a wet and winding road a couple years ago. My guess is that having the car slightly biased toward understeer will be a good thing, and this is backed up by comments made to me by skilled drivers at the Performance Center in Spartanburg a few years back.

Swapping wheels only takes a few minutes each but the dealer charges a flat rate for this work. Therefore I'll call this an hour labor and $120 saved by doing the work myself. The swap itself took me about 30 minutes but I spent a good hour with the setup, unrelated inspections, and cleanup. So I paid myself $120 / 1.5 hours or $80/hour. That's not my usual $100 sweet spot I usually need to justify working on the car but it's close enough for me.

Update on Oil Leak

A few weeks ago I noticed the hoses near the power steering pump were covered in oil of some kind. I had seen a condition similar to this before I replaced the power steering hoses a few years ago so I naturally assumed it was coming from poorly fitting hoses on the power steering fluid reservoir. Once I got the car jacked up in the front for the tire swap I managed to conduct an inspection and take a closer look at the problem. It turns out that the hoses going to the reservoir are dry and there is no obvious leaking coming from the vicinity of the reservoir, which throws out the alternate theory that it is simply ATF coming out of the vent in the reservoir cap as it sometimes does while revving at high RPM. I noticed a slight golden tint to some of the latest "drips" and realized that it was very likely engine oil -- and more specifically, fresh engine oil as I had just recently changed the oil.

Most of the oil appears to be dripping down the bracket for the power steering pump and there is only one place that I know of on these cars that leaks in that area: the gasket between the oil filter assembly and the block. If my diagnosis is correct, the best time to replace that gasket would be when I replace the power steering pump and alternator. So that big job just got bigger. Add to that my startling realization that the pulleys for both the water pump and power steering pump are indeed plastic and the fact that my water pump has over 60K miles in service, and I have an incentive to tear off and replace nearly the entire accessory section. I can't imagine doing all that work in one day even though the pros might be able to do it, so it appears that I may be driving the E46 for a couple of days when the time comes.

Technician's Comments on Lead Wear

I saw my technician earlier in the week as the E46 was in for its last warranty service so I naturally asked him about my findings and requested his take on things. In spite of an earlier life as a diesel mechanic and his familiarity with oil analysis in those engines, he remained as skeptical of the results as Jim from Metric Mechanic, but for a different reason.

Based on the many engines he's torn down over the years he suggested that the bearings don't usually fail catastrophically, but rather become scored in thin lines, as if you took the edge of a flat screwdriver and dragged it around the circumference of the bearing. That is usually the result of a large metal particle getting caught in the bearing, otherwise known as a particle streak. The good news is that it doesn't usually result in failure of the engine. The bad news is that it isn't normal and there's nothing I can do other than monitor it so that's what I plan to do.

Mileage: 190580, Labor Saved: $120

Saturday, April 17, 2010

First Parts Order for Accessory Overhaul

(Image: Screenshot of spreadsheet used to track parts for engine accessory overhaul)I recently made the call to do some work on the engine accessories including the power steering pump, alternator, water pump, engine driven fan and viscous coupling (fan clutch). Due to the labor involved I also decided to address the oil filter housing leak and accomplish both a coolant flush and power steering system flush. This should take care of a couple routine maintenance tasks and help preserve the vehicle's reliability for the remaining life of the engine.

Earlier in the week I leveraged my parts spreadsheet template and compiled a list of the required part numbers, quantities, and costs. Unfortunately, costs have grown to match the scope of the job, but I decided to buy the parts in a couple orders. The first order for $500 in various small parts came in from Tischer yesterday. I expect to place the final order next month and complete the job at that point. Inconvenient, yes, but necessary to ensure I carry no debt month to month and meet my strict savings targets.

The parts manager at my local dealer (one of the few guys remaining at the dealership since it was bought out in 2006, incidentally) knows me well and has offered to match Tischer's 20% discount on the two most expensive parts of this job: the alternator and power steering pump. Buying locally will avoid the hassle of dealing with the core charge refunds and should minimize the pain if I need to exchange the parts in the event they are defective. This is not to suggest that Tischer wouldn't do the right thing by me in that case, but their official policy is "no returns on electrical parts". My dealer maintains the same policy, but this is a case where a good relationship with the local dealer can come in handy. I'll have to send the gubmint their unfair share, of course, but sometimes peace of mind is worth more than an extra $40 in the bank.

Inspired by an article in the forums over at bimmerfest.com, I've also started to acquire the parts necessary to allow me to safely conduct what I define as an "Official" power steering flush. This will completely purge all of the old fluid from the system in one shot and ultimately preserve my investment in the new pump. And yes, the flush will be performed before the new pump is installed. By the way, if the article link is missing pictures (as often happens when people hotlink images into their threads rather than attaching them), I've locally stored a PDF version of the thread, complete with pictures, current to January 27, 2010 [23MB].

Note: Please respect my bandwidth and do NOT download the PDF unless you absolutely need it, and do not, under any circumstances, post a direct link to the PDF anywhere. You are welcome to post a direct link to this blog entry, however. Thanks for understanding.

(Image: Just a box of parts received from Tischer for the engine accessory overhaul)If you're wondering why I did not purchase the heavy-duty, high-flow Stewart Components water pump it came down to simple economics. I couldn't justify the price given the uncertain future of the engine. When I do the overhaul, I may, in fact, use the Stewart pump. It's a fine piece and worth the money -- provided you don't throw it away in 30K miles.

My search for aluminum pulleys revealed fine pieces from Turner Motorsport and UUC Motorwerks. The problem is that both companies only offer parts designed for racing. The pulleys are larger in diameter than the stock versions and therefore underdrive (lower the operating RPM of) the respective accessories. That is not required or even desirable for a street car and I'm not trying to turn this into a track car, nor do I care about extracting an extra few horsepower from the change in mechanical advantage. I simply want a pulley that won't suddenly self-destruct after one-too-many heat cycles. And yes, I'm fully aware that my stock plastic pulleys have a reasonable track record at 190K miles in service, but I think that's a case of luck more than anything else. Metal > Plastic.

Some googling lead me to BMP Design so I ordered their aluminum water pump and power steering pulleys. When I received the order confirmation email I was annoyed to learn only then that both parts were on backorder. The water pump pulley was expected in stock in a few days, and to their credit they did ship the part late in the week (four days later than their original ETA). An email exchange revealed that the power steering pump pulley had been on backorder for a month and their vendor could still not provide an ETA. The reason why they did not update their website to reflect this lack of stock escapes me, but I am hopeful that the part will arrive sometime in the next few weeks. If it doesn't, I'll just buy another OE pulley and call it a day.

Mileage: 191152, Parts $575, Parts Saved: $115

Friday, May 7, 2010

More Parts and Prep for the Accessory Overhaul

(Image: Closeup of metal water pump pulley and OE plastic power steering pulley)BMP Design finally came through with the aluminum water pump pulley. As you can see from the top half of the photo to the right, it's a good looking, sturdy piece. Unfortunately, they were not able to provide the aluminum power steering pulley so today I picked up an OE plastic pulley at the dealer while I was picking up some other parts including some fasteners for the under-hood insulation (a leftover from my windshield washer system overhaul) and the two M6 bolts needed to extract the water pump during the upcoming accessory overhaul. I've been in touch with a couple shops about machining a custom power steering pulley out of billet aluminum and black anodizing it, but it appears my installation timeframe may not permit me to install one. Since it's relatively easy to install the pulley later, however, I haven't ruled it out.

While my technician was busy running around handling the crisis of the minute, one of the other techs I chat with, "K", helped answer a few questions while he munched on a bagel and gathered tools to start work on a nice blue 335i in his bay. The first question had to do with the water pump itself and the aforementioned extraction bolts. He knew what I was looking for and managed to coerce another tech there to grab a couple of them for me out of his stash. He then pointed out that while the bolts were good to have on hand if the pump didn't want to budge, I probably wouldn't need them because in his experience most pumps come out pretty easily. His technique to extract the pump is to put a piece of cardboard between the radiator and the pump to protect the radiator, and then with both hands around the pump, rock it back and forth while pulling at the same time. I intend to do it this way initially and resort to the bolts only if necessary.

I then asked about the oil filter housing installation procedures. I noticed that the new gasket has two different faces -- one flat and one pointy. I naturally assumed the pointy end would mate with the groove machined into the housing but when I asked about the correct orientation he pointed out that it can only be installed in one way. Simple enough.

(Image: Closeup of M52 filter housing gasket)Another question related to reports online of housings continuing to leak even after the gasket was replaced. He said that's usually caused by the housing loosening up a bit, perhaps due to the gasket shrinking over time in combination with the stress created by the attached accessories. This results in the housing moving in relation to the block, which wears the surface and prevents it from sealing properly. This explains why some people wind up buying a new housing for around $300. Fortunately, given one experienced technician's appraisal online that this affects perhaps 5% of all installations, I won't be buying the part unless absolutely necessary. I'll risk a few days of downtime to save that money.

This led to a discussion on torque values of the housing bolts -- he said he did it all by feel. For a DIYer doing this for the first time on a cast iron block M52 that's probably acceptable, but I would be nervous to do try that on the M54's aluminum block, fearing I'd pull threads. The consensus online seems to be 21 ft pounds, which is openly suggested as a compromise between the maximum torque recommended for the bolt size and the desire to protect the threads and prevent wracking of the housing due to accessory load. I'll likely fine tune that number with additional research so if you're about to do this work don't take this at face value. Make sure you come up with the right torque spec for your application.

The only remaining parts to order are the power steering pump, alternator and some miscellaneous hardware. I'm waiting to purchase these parts based on the result of the airplane's annual inspection. A chat with my FAA-certified mechanic today revealed no surprises, thankfully, but the work isn't done until it's invoiced.

The OE power steering pulley lists for an astounding $59 (guess someone at BMW missed the memo that this is made out of plastic) so the parts guys took pity on me and gave me a slightly higher discount level than normal. They also discounted the hood insulation fasteners by a similar amount. The result? $20 in parts savings after tax is taken into account. After all, another Jackson in my pocket isn't a bad thing.

Trivia: While looking under the hood of that 335i, K told me that BMW is now using an expensive ($35/quart) power steering fluid in the latest cars. One can only wonder what the hell BMW's engineers are smoking lately. Surely if ATF did the job for years it could continue to serve that role, right? Oh wait...then BMW can't make $33 on a quart of proprietary fluid. But hey, it's "lifetime fluid", right, so we won't ever need to replace it! Problem solved! It's crap like this that makes me wonder if I'll ever buy another BMW, even if the 1 series M car recently spied in testing does eventually make it to our shores. I think someone at BMW needs to re-learn the engineer's mantra: keep it simple, stupid.

Mileage: 192050, Parts $80, Parts Saved: $20

Thursday, May 27, 2010

Failed Trailing Arm Bushing Leads to Suspension Overhaul

I know, I know. You just read the title of this entry and are now wondering to yourself..."self, is this guy nuts? He was just preparing to do an accessory overhaul and now all of a sudden he's doing a rear suspension overhaul? What the hell happened to the accessory overhaul?" Allow me to explain.

For at least the last couple of years I've noticed a certain sloppiness in the rear end of the car. It hasn't felt as "planted" as it once did. I diagnosed that as worn trailing arm bushings and put those on my list of things to do. Times being what they are and my schedule being what it is, I put the job off and rationalized the delay with my desire to completely overhaul the rear end of the car...eventually. So that brings us to the present day.

While I was washing the car last weekend I sensed something was wrong with the left rear wheel. The ride height seemed lower than normal, almost as if someone had decided to slam it while I wasn't looking. I reached into the space between the top of the tire and the lip of the wheel well to test my theory and found my fingers were a tight fit. I stepped back and walked around the rear of the car to compare it to the other side. That's when I confirmed that the left side of the car was slightly lower than the right. This was made all the more apparent by the fact that BMWs of this vintage are supposed to be slightly HIGHER on the left than the right when the car is unloaded because the vehicle is designed to accommodate the weight of the driver.

(Image: New rear suspension parts including springs and shocks)I initially concluded that the spring had failed. This is not exactly an uncommon problem here in the northeast states where salt is laid liberally on the roads in the winter. The design of the control arm tends to keep the lower portion of the spring bathed in salt spray, so it's not surprising that the springs eventually corrode and fail, and in doing so, drop the car almost an inch. As I walked back and forth to compare the rear wheels I also realized that, in addition to the usual negative camber apparent on both rear wheels, the left wheel was noticeably toe-in. Since the BMW spec for rear wheel toe is a mere 0.3 degrees positive, I knew something was definitely wrong with the rear suspension.

First thing Monday morning I went to the dealer with a list of parts. I originally thought I'd pick up one M-sport package spring, but as it turns out BMW only sells them in pairs (BMW part number 33-53-9-059-403, $288). A earlier review of my maintenance schedule revealed that the shocks had been in service for exactly 100K miles (10K more than the last time I replaced them), so I added shocks (33-52-1-090-831, $268), shock mounts (33-52-1-092-362, $64), shock tower reinforcement plates (51-71-8-413-359, $41), and all the related hardware to the list before settling up with the parts guys for a cool $805 including a 20% discount and a $52 donation to the government.

If you're wondering why I ordered locally when Tischer would have been able to meet that discount level and help me avoid the tax, the reality is I wanted the option to bitch at someone face to face if the springs turned out to be the wrong version. This was a distinct possibility given that BMW does not publish the spring part numbers in the ETK and therefore make them easy to confirm with the BMW community.

As I left the dealer and drove to work, I thought about my plan of action and figured I'd do the springs and shocks and call it a long day. When I got out of the car at work, I once again attempted to check the gap between tire and wheel well just to make sure it wasn't getting worse. Surprisingly, the gap seemed to be a bit larger and the wheel didn't seem to have as much toe-in. And that's when it hit me. The problem wasn't the spring, but the trailing arm bushing, which was causing the entire arm to pivot left and right.

Since trailing arm bushings are a pain in the ass to replace on the car even if you do have the special pusher/puller tool to get the job done, I quickly found myself on a slippery slope. If the trailing arm bushings are shot, surely the other bushing and ball joint on the trailing arm couldn't be far behind. That and my desire to replace the right wheel bearing (with 193K original miles) would justify pulling the arms and having all new parts pressed in on a bench press rather than use lots of special tools I'd have to source myself or borrow from my technician.

Naturally, I continued, if the bushings on the trailing arm are sloppy no doubt the inner control arm bushings have been taking a beating for the last several years as well. Unfortunately, it's not possible to remove the inner bushings without moving the differential aft a few inches to gain access to the bolts. And if I need to disconnect the differential, I figured I might as well pull it for an overhaul (bearings, seals, reset the lash, repaint). Accelerating down the slope beyond Mach 1, I further rationalized that if the subframe were to be sans differential and control arms, surely it couldn't be that much more of an inconvenience to pull the entire subframe out of the car to clean off all the rust and powder coat it, while at the same time replace the subframe bushings with upgraded M3 parts.

Now beyond the area of maximum aerodynamic pressure at Mach 1.2 or so, I jumped to the conclusion that this would be a perfect opportunity to have a local welder stop by to install the M3 subframe reinforcement plates. I mean, heck...this car might make a mean track rat someday, and it would be stupid of me to track it without those reinforcements. Of course, since mobile welders don't come cheap (and the one closest to me charges a flat rate) I figured I might as well have him weld in both the swaybar tab and RTAB pocket reinforcement plates while he's at it.

I think you can see where this is going. The parts list is long and expensive and most of that list is on its way to me as I write this. The mobile welder is one phone call away. I've spoken to a powder coater about prepping and painting several of the rustier components while they're off the car, and I even managed to convince Dan at diffsonline.com to pick up my differential at the Bedford Airport when I fly it up there in the 172 on a post-annual test flight. There's no stopping now. It's going to be one hell of an adventure and the greatest test of my DIY skillset to date. The plan is to begin disassembly this weekend but holiday plans may have something to say about that. In any case, it appears that the E46 will get to flex its muscles for a couple weeks. I hope the E36 doesn't get jealous. Stay tuned!

Mileage: 193000, Parts $805, Parts Saved: $205

Saturday, June 5, 2010

Axle Remanufacturing Options

For the past week I had been going back and forth about the need to regrease the CV joints in the rear axles during the rear suspension overhaul. I would have preferred to do the job myself and save a ton of money, but given the scope and logistical headaches of this job, my schedule, and the cost of my time to rework them, I ultimately decided to go with a pair of "remanufactured" BMW output shafts.

Of course, "remanufactured" is a somewhat disingenuous term as applied to those parts. Normally, the term "remanufactured" refers to a part that has had all wear components replaced with new parts. The unfortunate reality is that BMW does not replace the CV joints on their "remanufactured" output shafts. The better word to describe what BMW does is "overhaul" the joints, which amounts to disassembly (where possible), cleaning, inspection for damage, regrinding, and then regreasing and installing new boots and clamps. Basically, this is the same kind of thing a pro technician or DIYer can do (sans grinding), only a hell of a lot more expensive.

I looked into having a professional remanufacturer overhaul my axles but the one I spoke to (raxles.com) said they couldn't touch BMW axles anymore because they were no longer able to source new CV joints from Germany. Both raxles.com and Mike Miller of the BMWCCA confirmed that due to a "bear claw" design of the outer joint, few if any remanufacturers can disassemble the joint in the same way an average DIYer can disassemble the inner joint. It was not always this way but BMW changed the design for some stupid reason, so now all we have are more or less throw-away parts. The best thing to do, therefore, is make sure your axles don't fail.

As Mike Miller commented, however, he has yet to see a failure of a CV joint on the back of a BMW that wasn't due to failure of the boots (which causes the grease to leak out and moisture and dirt to get in and destroy the joint in short order). So it's safe to say that if you are so inclined and have the time to invest in the process. you can clean them in a bucket of solvent, regrease them and install new boots for considerably less than I paid for each of the BMW "remanufactured" units. Of course, do that job wrong and you'll be buying BMW remanufactured shafts in any case. I could not take that risk, and with a nearly 25% discount on the parts from my dealer (a total of $750 without the core charge), buying OE up front seemed like the best thing to do.

Rear Suspension Overhaul - Disassembly Day One

(Image: State of the rear suspension at the end of the first day of the overhaul process)I had hoped to begin the suspension overhaul last weekend but I wound up committed to other things for the holiday. It was probably just as well, since I was still busy sourcing parts and dealing with the logistical headaches associated with a project of this magnitude. And as it turns out, my technician went on vacation this week so while I didn't expect to need his counsel to dismantle everything and get the parts out for overhaul, I knew full well it would be preferable to have him a mere phone call away before I started tearing into this.

The vast majority of the parts came in from Tischer and my local dealer yesterday and I spent a couple hours inventorying everything last night. This was a very big and tedious process largely because I ordered virtually all new hardware to replace rusted or otherwise damaged parts. As it turned out, they shorted me a few parts, including a wheel bearing. That shouldn't delay me as long as the parts arrive before mid-week.

I set the goal for today to disassemble the entire rear. Needless to say, I didn't get that far. This is what I did manage to accomplish:

  1. Remove the interior panels from the trunk.
  2. Remove the wheel nuts.
  3. Remove the sway bar.
  4. Partially disassemble the brakes and disconnect the wear sensors
  5. Remove the nuts holding the driveshaft to the differential.
  6. Remove the external torx bolts holding the axles to the differential.
  7. Push the driver's side output shaft out of the hub.

The first snag of the day came when I attempted to use my 36MM socket to remove the axle nuts. Too bad I got my signals crossed and bought the wrong socket. The E36 uses 30MM nuts on the rear. So, I jumped in the E46 and ran over to Eppy's to buy a 30MM impact socket. Fortunately that only ran me $11, but I naturally saw some other sockets I needed to the total bill jumped to $125. This deviation blew about an hour of my day.

I quit for the day after about 5 hours of work when I realized I was not able to press the passenger side output shaft out of the hub using an air hammer or the old fashioned hand-operated kind. This will require a two arm puller, something I plan to buy tomorrow. I figured I could probably leave the output shaft in the trailing arm and let my local indy tech press it out when they press out all the bushings for me Monday, but I have to go the tool store anyway to pick up a set of impact sockets to remove the subframe. There is no way those rusted bolts and nuts will come out using breaker bars. I had a hell of a time just removing the output shaft bolts (yea, even the ones my tech removed a couple years back when he did the left rear wheel bearing, and yea, after I coated them earlier in the day with some PB Blaster penetrating oil), so I'm convinced I'll need air tools and appropriate sockets to make that happen.

The good news is that there is nothing to stop me from removing the differential first thing tomorrow, which is absolutely necessary for me to fly it up to diffsonline on Monday morning. I'm doubtful at this point whether I will be able to reassemble everything by next weekend simply because I don't believe my parts will be back from powdercoat until late in the week and I still have to schedule my indy tech at that point to press all the new parts in. Worst case is the car will be down for two weeks and I'll spend next weekend taking a well-deserved break. We'll have to wait and see.

Mileage: 193332, Parts: $1572, Tools: $125, Supplies: $30, Parts Saved: $400

Sunday, June 6, 2010

Rear Suspension Overhaul - Disassembly Day Two

I'm not a factory trained BMW technician, but I play one on the Internet. :-)

I began the day with a stop at Eppys to pick up some tools. Specifically, I bought an OTC front hub puller to press the passenger side axle out of the drive flange, and a nice set of SK impact sockets simply because I didn't have any and knew I would need to leverage my air tools in a big way today.

I arrived at the garage and did the following, in order:

  1. Press the passenger-side axle out of the drive flange.
  2. Break loose the differential fill and drain plugs and then drain the oil.
  3. Remove the differential.
  4. Remove the brakes and parking brake assemblies.
  5. Disconnect the shock from the trailing arm.
  6. Disconnect the upper and lower control arm from the trailing arm.
  7. Disconnect the trailing arm from the body at the RTAB.
  8. Destroy perfectly good speed sensors while attempting to remove them from the trailing arm.
  9. Curse the speed sensor design.
  10. Remove the parking brake cable assembly from the trailing arm.
  11. Curse the parking brake cable assembly design.
  12. Disconnect the control arms from the subframe.
  13. Remove the subframe.
  14. Jump for joy (mentally, not physically...as my body was too tired to stand, let alone jump, at this point).

In short, I completed the disassembly process and the vehicle now stands in the condition shown in the picture. This was a solid four hours of work, which brings the total disassembly time to nine hours.

Some highlights:

(Image: State of the rear suspension at the end of the second day of the overhaul process)I spent a few moments examining the old CV joints. I found all the joints very loose and the outers with some play. I think if I had chosen to regrease them in the field, the new, thicker, grease would have taken up some of the wear tolerance and no doubt tightened up the joints somewhat, but my guess is they would not be as tight as the axles I received from BMW. And there's a very good reason for that -- most remanufacturers replace the balls with parts one or two thousandths oversize to compensate for the wear in the carrier. The result is a joint with the proper tolerances.

I was pleasantly surprised to find the differential gear oil almost like new. That was certainly not the case when I changed it last time, but I think that was the result of the fill at that time effectively cleaning the inside of the differential following my error of leaving the original differential oil in the unit for over 120K miles.

When I disconnected the control arms from the trailing arm the cause of that squirrely feeling in turns became obvious as the trailing arm, now hanging from the RTAB, sort of bounced around in all axes -- something it is clearly not supposed to do. And in fact, a close look at both bushings revealed that the metal core had separated from the rubber. Note to self -- change these blasted things more often than every 193K miles.

I knew before I started this overhaul that replacement of the trailing arm bushings would likely have solved perhaps 80% of the crummy handling, but I also noticed that the upper outer ball joints were quite loose. If you've never tried to move a new ball joint, let's just say it takes some effort. These ball joints flopped around with a flick of a finger. The remaining control arm bushings were reasonably tight, but it doesn't take a lot of give in all the individual bushings to translate into that 20% sloppiness, which I'm sure would have annoyed me no end had I not taken the obsessive-compulsive approach to the repair.

Unfortunately, I had to destroy the speed sensors to remove them from the trailing arms. In spite of the sensor body being plastic (you know that stuff that doesn't rust or otherwise react with nearby metals) it somehow managed to bond itself to the bore in the trailing arm. I tried to be careful with it. When that didn't work, I used a universal alignment tool (UAT) and a socket as a drift to remove it with prejudice. Looks like I'll be buying new sensors. Oh well. That's life in the big city. By the way -- BMW makes a stink about coating the bore with a special German-sourced grease during reassembly. My tech said he sparingly uses a common lithium-base grease, so that's what I will use as well.

The speed sensors must have been shacking up with the parking brake cable assembly, as that too bonded with the bore in the arm and really gave me fits. Fortunately, because the end of the cable that mates with the arm is metal, it was able to take a bit more abuse from the UAT. That in combination with a small screwdriver as a pry bar and a bit of tugging on the cable in all directions pulled it from its corroded confines. Of course, I won't bore you with the disassembly procedure of the parking brakes which made this all possible. That will be covered in an upcoming DIY, should I wish to relive the horror at some point for the benefit of my readers.

I found removing the differential to be reasonably easy in spite of its weight (80 pounds or so...about the weight of a bag of concrete). The jack certainly came in handy. I'm not looking forward to reinstalling it, however, as everything is easier when Sir Newton is helping. Maybe I can flip the car upside down for that part. ;-)

In spite of being a huge hunk of metal, I found the subframe to be reasonably light, and that's a good thing because it fits very tightly to its mounting studs and bolts. I really had to jimmy it back and forth to get it to come off the front studs. Of course, that may have had more to do with the rear pivoting down somewhat under its own weight, but we'll see.

As for the subframe bushings, I'd call the differential mount bushing toast, which isn't exactly a surprise -- the forces on that bolt even on the street are pretty substantial, and on the track with manual transmission they're high enough to break a grade 10 bolt (or rip the entire bushing carrier from the subframe). The two front bushings and one of the rear bushings had noticeable cracks in them. Whether the cracks were merely a surface phenomenon or indicative of impending failure, I'll never know. And I don't really care, since they'll all be replaced. The rears are slated to receive the stronger M3 parts as well.

Tomorrow I'm taking a vacation day as planned and have several things to accomplish:

  1. Return the drive axles to the dealer for a core credit. It's only $100, but I'm not in the business of giving interest free loans, so I want it back.
  2. Drop all the parts off at my local tech to have him press everything out in prep for powdercoating. He said he knows a good fabricator, so I'll have him weld on the swaybar tab reinforcement kit. That will cost more, but will make the mobile welder's job a bit easier and hopefully simplify the logistics a bit, as the part will then be ready for a full sandblast and powdercoating.
  3. Fly the differential up to Dan at diffsonline so he can get busy with the overhaul and (hopefully) have it back to me by the end of the week.

The remainder of the week will amount to shuttling the parts back and forth, something I hope to do with a minimum number of vacation days. I do have a bunch to do at my real job and it's not getting done while I'm wrenching, that's for sure.

Mileage: 193332, Tools: $240

Wednesday, June 9, 2010

Rear Suspension Overhaul Update - Parts Sent Out for Disassembly

(Image: Closeup of new style rear trailing arm bushing)On Monday I managed to get up reasonably early so I could run over to the dealer and get the core credit on the axles and then run the suspension parts over to my local indy technician, Mr. M Car, which just so happens to be located at one of my old stomping grounds, and the location of my first skydive, Monmouth Executive Airport. I arrived to find Don, the owner, in a nondescript hangar filled with an assortment of nice cars, most of which were BMWs.

I told him that I wanted all the bushings, ball joints and bearings removed from the parts in prep for refinishing. I also mentioned the need to MIG weld the swaybar tab reinforcement kit to the subframe and he told me that he knew a fabricator on the airport grounds that could do a fine job. He even read my mind when he told me that the kit needs to be installed properly or else it would interfere with the swaybar mounting tab or the hardware used to fasten it. My instincts told me this wasn't Don's first rodeo and I figured I'd found the right guy for the job.

As I looked around the shop I saw a couple engines in various states of assembly as well as some tasteful memories of money-shfts gone by and the proverbial light bulb illuminated in the dark chasm that often masquerades for my brain. I asked him whether he could install new bearings and seals in my differential and help prep it for refinishing. He quickly admitted to his share of knowledge of BMW differentials, including his insistence to use German bearings (SKF or FAG) rather than cheap Chinese crap. So, rather than haul that 80 lb bag of concrete up to Massachusetts and back, and pay Dan a cool grand for what is just this side of a spray paint overhaul (no gear changes or LSD upgrade), I told Don I'd bring my differential to him later in the day, and that's exactly what I did.

Since there wasn't much for me to do on the car while I waited for Don to prep the parts I went back to the salt mine on Tuesday. Last night I managed to place yet another order with Tischer to cover a few miscellaneous parts I'll need for reassembly. First and foremost was a replacement for the ABS sensor ($110!) I broke during disassembly. While under the car I could not overlook the rubber hose that connects the fuel filler tube with the fuel tank. It looked so heat damaged and brittle that I considered that an essential replacement for safety reasons. The only problem? That simple hose is $66. I also ordered four (4) new large retaining washers for the subframe simply because the old ones were rusty and some simple math convinced me it would cost more to prep and paint the old parts than it would to buy new. I expect that order to be here Friday or Monday at the latest.

I also noticed that during disassembly the electrical plug that connects the body harness to the brake wear sensor practically disintegrated in my hands (12 years of exposure to countless heat cycles will do that to plastic). I failed to find the plug in the ETK so I went to the dealer. The parts guy couldn't find it either so he called the BMW tech line and they gave him what we both hoped was the correct part number. It's on order and I expect to see that later this week as well.

And if you're wondering about the picture, that's a closeup of the new "split" style trailing arm bushings that were reportedly originally developed for the Z4 M Coupe. The TIS recommends replacement of flange-type bushings with the new split type, so this is not exactly an out-of-the-box upgrade. I can't wait to get the car back on the road to try them out.

Mileage: 193332, Parts: $245, Parts Saved: $80

Friday, June 11, 2010

Rear Suspension Overhaul Update - Parts Returned

Yesterday I exchanged some email with Don.

(Image: Pre-terminated wires and connector required to fix brake wear sensor wiring)First of all, he let me know that he would have the parts ready to go shortly but said he was unable to remove the inner bushing from the lower control arms. The arm is actually split into two pieces in that area and he said he would likely crush or bend the arm trying to remove the bushing. My dealer tech told me much the same thing but I figured that he was saying that simply because the cost of his labor usually requires him to buy new arms vs. new bushings. Guess not. So last night I placed an order with Pelican Parts for Lemforder (OEM) rear lower control arms with bushings pre-installed. The damage? $50 each or about $50 cheaper than the OE versions. The perk? I won't have to paint the lower control arms to get the "like new" look I'm trying to achieve.

Don also offered to do the differential overhaul consisting of new bearings and seals, resetting the lash and a rattle can paint job for $750. We discussed the idea of replacing the mounting bushings and he said that he would do those for the cost of parts. I did a couple quick part lookups on realoem.com and realized that the bushings retailed for about $15 each so I figured I'd go ahead with that option. In for a penny, in for a pound, right?

A few thoughts then ran through my head. Would it make sense to press new bushings into the existing cover? Perhaps not because...

  1. Don would have to waste his time swapping the bushings. Not a cost to me, per se, but a cost to him that I'll ultimately pay for in some way. There ain't no such thing as a free lunch.
  2. I'd have to waste my time running the cover over to the only person I knew with a blasting cabinet -- my aircraft mechanic -- in order to dress the part up enough so it would look at home on the newly repainted case.
  3. There is a reason why BMW does not advocate pressing new ball joints into front lower control arms made of aluminum (a la E46). I won't belabor the point here, but think metal fatigue.
  4. A brand new cover with pre-installed bushings is only $100.

If you've read this far you already know what I did. A new cover and related hardware as well as a speed sensor for good measure is on the way from Tischer (getbmwparts.com). As I placed the fifth order with in them in the last couple of weeks I added a comment to the order form I knew Jason and Evan would read: "How much more do I need to buy before you guys increase my discount level?" :-) I'll spare you the details of the response, but apparently I'll need to buy a BMW dealership if I want a higher discount. Hmmm...if only I had a spare $15 million burning a hole in my pocket.

Today I made some follow up calls to a couple powder coaters. One never returned my call from yesterday and didn't answer today either. The second guy called back but told me that it would take him a bit more than a week to get the parts back to me. That meant if I delivered them Monday I'd waste the following weekend waiting for the parts rather than beginning reassembly as planned. I quickly realized that powder coating just wasn't going to work out, and I would be forced to prep and paint the parts myself using rattle cans. This isn't all bad news. It removes the question of whether the powder coat would interfere with reinstalling the brake guards on the control arms (it's a tight fit as is...can't imagine how would work with 3-4 mils of powder coat). It also will save me anywhere from $300 to $500. And given how I've been bleeding money lately, that's a welcome change of pace.

This afternoon I picked up the control arms and trailing arms from Don. He charged me 2.5 hours and that's not bad considering how long it would have likely taken me to do the job. I paid the bill and took a few minutes to shoot the shit, as it were.

(Image: Closeup of AKG Motorsport rear subframe reinforcement installed)He asked me to confirm I was planning to use the new split type RTAB and of course I answered in the affirmative. He said that was a good choice because the new bushings use a higher durometer rubber than the prior version and the outer diameter of the bushing (uncompressed) is somewhat larger than the opening in the arm. Installing it in the arm compresses the rubber further which helps keep that center metal bushing where it should be. Unfortunately, he mentioned that he has seen cases of the bushings "walking" slightly out of the arm so he said he'll drill a small hole in the arm in an inconspicuous place and install a screw to lock the bushing to the arm. Easy enough to do with a minimum of consequences, given that the arm is steel rather than aluminum.

This eventually led to a discussion of the body / subframe reinforcement plates I had planned to install. He and one of his staff quickly retorted that the chance of the E36 body failing in that way was so remote as to make it not worth the hassle, particularly on a street car, and one with an automatic transmission to boot. This wasn't exactly news, but it was interesting to hear it from guys that race these cars. Don said that the three cars he'd seen damaged were all driven by the "younger element" who tended to slam the throttle around, dump the clutch, accelerate rapidly over potholes and generally abuse the cars on the street or the track. This advice combined with my desire to get the car back in service AND reduce the bleeding coming from my wallet has convinced me to NOT install the reinforcement plates after all. That should save me at least $300 for the mobile welder plus the usual risk of fire that comes along with welding a car with the fuel tank installed. I haven't decided yet whether I'll sell the plates as I may use them eventually, but contact me if interested in a small discount off retail.

Fortunately, welding the AKG Motorsport swaybar tab reinforcement kit on the subframe was easy to do with the subframe removed from the vehicle. As you can see in the picture, Don had his fabricator install the kit and the the work is beautiful. It is better than the Turner kit, in my opinion, by the virtue that it includes an extra piece that is used to box in the structure, thus significantly enhancing the strength of the modification. Truth be told, the kit is overkill for a street car equipped with the stock rear swaybar, but you really didn't think I was going to keep that on there forever, did you? After all, there is a method to my madness.

This weekend I plan to:

  1. Install the new brake wear sensor wiring I picked up from the dealer this morning (pictured)
  2. Scrub the underside of the car's body while I have the opportunity
  3. Prepare, prime, and paint all the parts I'll take back to Don on Monday morning

Mileage: 193332, Parts: $205, Parts Saved: $80, Labor $235

Sunday, June 13, 2010

Rear Suspension Overhaul - Parts Prep and Body Cleanup

(Image: Using a citrus based degreaser to strip rear control arm of grime)The first step to any paint prep is to degrease the parts. This presented a question -- what degreaser to use? Traditionally, I've used mineral spirits shot through a spray wand attached to shop air to degrease the airplane's engine and cowl area. It strips grease and oil very well and then dries quickly with little or no residue. And, in fact, most enamel (think rattle-can) paints suggest stripping the surface of the area to be painted with mineral spirits, so I know they are compatible. The problem, of course, is that mineral spirits is a petroleum product and as a consequence, not particularly environmentally friendly. It's also flammable as hell.

Based on some research online I've found that the age of bio-friendly citrus-based degreasers has arrived, and guess what -- unlike most "environmentally friendly" chemicals, they actually work. So while at Home Depot yesterday I bought a gallon jug of Zep Heavy Duty Citrus Degreaser, a pair of black nitrile rubber gloves to protect my hands, and a sturdy nylon brush. I also picked up several rattle cans of automotive primer and some satin black finish coat, as well as a gallon can of mineral spirits that I figured I'd use to remove whatever residue the citrus degreaser might leave behind just prior to painting.

Back home, I got to work and poured about 1/4 gallon of the degreasing fluid into a stainless steel bucket and used the brush to transfer the degreasing fluid to the parts at full strength. I scrubbed the parts and then rinsed them with water and was pleasantly surprised at how effective the process was at cleaning all the penetrating oil, brake dust, and other grime from the parts. I'm sold on citrus degreasers and can wholeheartedly recommend them if you want to be environmentally correct AND come out smelling as sweet an orange grove rather than the butt end of a refinery.

I then set up the compressor, equipped my die grinder with a medium grit abrasive disc, and sat down with the parts to begin the tedious process of cleaning off the rust and scuffing the existing paint to give it a "tooth" appropriate for painting. I spent a solid hour doing this and managed to clean up the parts pretty well, but ultimately realized that the damage due to rust on the subframe was a bit deeper than originally thought. I knew I could not fully clear the surface of rust or smooth out the surface in preparation for paint with anything but an electric grinder equipped with a hard-abrasive wheel -- something I did not have at the moment. At that point I realized I'd simply have to bite the bullet, accept a delay in the reassembly process, and get the parts professionally sandblasted. I left the garage for the day somewhat disappointed, but still satisfied that I gave it the old college try.

(Image: Results of scrubbing and degreasing rear body while suspension is removed)Today, after washing and applying some paint sealant to the E46 to protect it from the elements it now braves on a daily basis, I got to work on the E36. First, I managed to replace the connector on the body harness of the E36 for the rear brake sensor. Although I expected to have to solder in the pig tails purchased this week along with the new connector, I managed to remove the existing pin sockets from the broken connector and insert them, unmodified, into the new connector.

As it turns out, that connector is equipped with a locking tab and that, in combination with small barbs on the pin sockets, locks the sockets into the connector. I tried to gracefully pry the locking tab up to slide it back and out of the way, but it broke. What a surprise. So I used a micro screwdriver to pull the remainder of the locking tab away from the connector and then pushed the barbs in far enough to release the sockets from the connector. To install the new connector, I simply reversed the process and snapped the locking tab closed. Done!

Since the brake wear sensor is just a switch of sorts I doubt the polarity of the wiring matters, but for future reference I noted the following wiring convention:

I put the unused pigtails for the sensor wiring in my spare parts drawer before moving on to the messiest part of the day. Using some of the degreasing liquid diluted 50/50 with water, I got under the bottom of the car and used the nylon brush to scrub everything in sight, particularly the areas that would be inaccessible once the subframe was reinstalled. I let the liquid soak in a bit and then rinsed it with water. The color of the water I rinsed off the garage floor was a black as night, so I knew the degreaser had done its job. I then looked up at the body and confirmed it -- the cleaning process exposed body color and gray primer that likely hadn't seen the light of day for many years. I'm now comfortable that the body won't clash with the freshly painted suspension parts.

This week I have to get the parts sandblasted, painted, and then back to Don so he can install all the new bushings, bearings, and ball joints. At this point I am uncertain as to whether I will be able to do any reassembly this weekend, but if I can get the subframe installed in order to get my rear jack point back I'll be happy.

Mileage: 193332, Supplies, $120

Friday, June 18, 2010

Rear Suspension Overhaul - Parts Return from Powder Coating

Yes, you read that entry title correctly. After a lot of back and forth on the subject, I managed to get the suspension parts powder coated with a turnaround of four days. I picked them up from Mike at Shore Powdercoat today around Noon and immediately drove them over to Don at Mr. M Car along with a box of parts he'll press into them over the next few days.

Overall, I'm very happy with the finish. While the subframe in particular still shows the deep scars of the rust damage (click on the pictures to see what I mean), I think I can rest assured that the sandblasting removed what remained of the rust and the powder coating effectively sealed the steel so it should no longer be an issue for the remaining life of the car.

I asked the powder coater to avoid sandblasting the smooth bushing surfaces on the parts but they did anyway. Fortunately, according to Don, that should not be an issue, and at least in the case of the RTAB the extra friction might be a good thing.

I also asked them to sandblast the parking brake attachment assemblies to clean them of a ton of crud that refused to come off with the degreasing agents and solvents I had on hand but I requested they not paint them because clearances can be an issue with those parts. They painted them anyway, and when Don saw that he expressed some concern about it, but I noticed that the parts seemed to actuate without any binding and they do look a hell of a lot better than they did. I guess I'll find out how they work when I attempt to install the parking brakes.

And speaking of brakes, I bent one of the brake shields trying to remove it from the rusted trailing arm last weekend so I ordered new brake shields at $15 each. Since they must be put on before the drive flange is pressed into the bearing, now is the time to do that. And, of course, I ordered all new hardware to go along with that because nothing looks more half-ass than new parts put together with old, rusty fasteners. And if you're wondering why I didn't just paint the fasteners, it's because the ratchet would likely mar the paint and the rust would soon return. The new fasteners are zinc plated and that should help prevent rust from forming for some time.

Before I left to go back to the office, Don mentioned he was still waiting for bearings for the differential but he expects to see them Monday. He also suggested the parts would be ready by the middle of next week. If he sticks to that schedule I should be able to begin reassembly Thursday or Friday. In the meantime, this weekend I plan to install the new fuel tank hose and a new muffler heat shield I bought to replace the original part that was damaged a long time ago when one of the muffler mounts failed. The heat shield is largely a cosmetic fix, but I've become very good at justifying such things lately.

Mileage: 193332, Labor: $295

Sunday, June 20, 2010

Rear Suspension Overhaul - Miscellaneous Preassembly Tasks

Earlier in the week I spoke to my technician about two issues:

  1. How to press the axle shafts into the drive flanges. Specifically, I asked him whether it was possible to press them in most of the way by hand and then use the nut along with an air wrench to pull the axle in. He smiled and said "sure, you can do it that way if you want to ruin the axles!" He quickly retorted that the proper way to do that is to use the BMW special tool or an equivalent that bolts to the hub and threads into the axle shaft to pull the axle into the flange. Fortunately, he agreed to loan me the necessary tool. All I have to do is bring him one of the axles to make sure he gives me the correct threaded component. Have I said lately how important it is to maintain a good relationship with your local BMW technician? :-)
  2. How to align the trailing arm bushing carrier (what BMW calls the "console") for zero preload at ride height. I knew there was a special tool for this task but he said that he no longer had the tool in the shop because it broke and it really wasn't necessary in the first place. He said he uses a similar technique that involves a generic straight edge. I've known about that technique for some time but had hoped that I could use the tool because it takes the place of the extra hands that will no doubt come in handy while I hold a couple box end wrenches and torque the bolt to 110Nm (81 ft*lbs). If that doesn't sound challenging, consider that the torque is just shy of that required for a wheel lug bolt. Yea, that will be a piece of cake. Riiiiight.

Yesterday I did a bit of minor preassembly work while I waited for parts to come back from Don.

To start things off I picked up the new muffler heat shield from the dealer in the morning. While I was there, I asked the parts guys for three wheel lug bolts to replace the ones whose threads were damaged when I used them with the special tool to press the axle shaft out of the drive flange. Always willing to help, my "alternate" tech, K, overheard my quandry and responded with a gesture of three near-new lug bolts from his spare parts bin...free of charge, of course. Cool guy, eh? He also mentioned that he was looking forward to seeing the results of my efforts and I told him he'd see it soon for an alignment to wrestle the rear toe and camber back into spec.

Back at the garage, while pulling the old heat shield out, I realized that the heat shield actually comes in two separate pieces and I had only ordered the larger of the two ($55). A quick call to the parts department solved that problem. The smaller part ($35) is on order and should be here by Wednesday. As it turns out, one of the heat shield retaining nuts was also missing in action (it probably fell off some time ago since I certainly did not remove it during this project) so I ordered more. They were only available in a package of ten, but rather than something like 45 cents each retail the parts guy took pity on me again and gave them to me for one penny over cost, or 25 cents ($2.50). Those will be here Wednesday too.

I then installed the new fuel hose that connects the filler neck with the tank. The hose attached to the filler neck side easily but the end that attaches to the barbed nipple molded into the tank gave me fits as there was essentially little to no clearance between the nipple and the body of the vehicle. I finally managed to wiggle it on but I had even more difficulty trying to fit the clamp to far enough down the tank nipple. It's definitely on there now and it looks great, but what a needless pain in the ass. You'd think BMW had never built a car before this one. All they had to do was mold the tank to push the nipple a 1/4" farther down and this would be a non-issue. The perk of this task was that I realized I had picked the right time to do this. I can't imagine replacing the hose with the upper control arms, etc. in place as there is simply no clearance to get in there.

Next up was pre-assembly of the shocks. First of all, I discovered that I could not remove the top nut that secures the mount to the rod from the existing shock assemblies because I couldn't securely grab the shock rod and prevent it from rotating. This prevented me from reusing the top cup washer that I originally chose not to order because it seemed to be in great shape. This also highlighted the fact that if I couldn't remove the nut, there was a pretty good chance I wouldn't be able to tighten it on the new assemblies either. I also discovered that I neglected to order a very small washer that fits inconspicuously below the bottom cup plate, presumably to add strength to the cup plate where it rests on a small ridge machined into the rod. I thought briefly of reusing the washer from the old assemblies but closer examination revealed they were both badly rusted and unusable. A quick call to the parts department fixed the problem and new washers are on order.

I then reviewed the first task of reassembly – installation of the subframe. The subframe attaches to the body with two studs in the front and two bolts in the rear. Per the TIS, the studs must be torqued to 120 Nm (88 ft*lbs), while the two nuts that hold the subframe to these studs as well as the two rear bolts must be torqued to 140 Nm (103 ft*lbs). I soon wondered how to secure the studs to the body. While they have a hex nut cast into them, the stud shafts are too long for even the deepest of sockets so I concluded I'd need a 24 mm crow's foot socket to first torque the stud to the body and then a regular socket to torque the large grade 10 nut that would hold the subframe to the stud.

The last task of the day involved prep and paint of the fittings that mate the parking brake cable assemblies to the trailing arms. I used emory cloth to remove all the rust from the fittings but made a point of not painting the portion that mates with the bore in the trailing arm for fear that the close tolerances would prevent installation. You can see the results in the foreground of the heat shield picture, above.

Today I did some Googling to find out if there was a better solution for R&R'ing the shock mounts than a set of vice grips. Ultimately, the terms "oval shock socket" revealed what I needed to know, including the fact that Lisle makes a “universal” kit of oval sockets (Lisle Part number 20400). That led to the realization that my local tool shop, Eppy's, carried the kit. I ran over there today with one of the old shock assemblies and confirmed that one of the tools in the kit fit the BMW application before I plunked down the whopping $10 for the set. While there, I also picked up a set of metric crow's foot sockets ranging from 8 to 24 MM (Astro Pneumatic Tool Part number 7115) for $36 and considered it money well spent.

Mileage: 193332, Parts: $90, Parts Saved: $20, Tools: $50

Thursday, June 24, 2010

Rear Suspension Overhaul - Assembly Day One

Yesterday I picked up the parts from Don and paid him for a job well done. He managed to get all of the bushings, bearings, and ball joints installed without scratching any of the parts. And as it turned out, he did not have to drill the trailing arm to secure the RTAB because he was able to press it in without using any lubricant. That in combination with the sandblasted surface and Vorshlag shims should keep the RTAB well positioned. He also finished the differential earlier than expected, complete with new bearings, seals, cover, speed sensor, and all new hardware along with a fresh paint job. It looks brand new.

Today I began the day by visiting Eppy's to pick up a small set of 1/2" drive extensions because I knew I'd need them today in several places. I tried to buy SK to match the bulk of my ratchets but they only had a set of wobble extensions in stock. So I was forced to buy a small set of three extensions (3, 5, and 8") from an offshore vendor. I also stopped by Home Depot and picked up a couple three foot pieces of 1/8" thick aluminum angle to help with the RTAB console alignment and a future task involved in the front suspension I expect to tackle in a few months.

By the end of a five hour work session in 95 degree heat I had managed to install a bulk of the suspension. It went largely as expected with a few exceptions:

I managed to dial in both the camber and toe settings pretty well based on pictures I took prior to disassembly and applied the final torque on the control arm outer bolts. I could do this because they are ball joints and will naturally rotate as I lower the suspension down to normal ride height. I can't apply final torque to the inner bolts that secure the control arm bushings to the subframe because the preload on those bushings must be set at normal ride height and I can't achieve that until the wheels are reinstalled and they are lowered down onto a set of ramps for clearance purposes.

The remaining components to be installed include the parking brakes, wheel brakes, axle shafts, differential, swaybar and muffler. Tomorrow I'll install and adjust the parking brake and wheel brakes first because I'll need those functioning to prevent the drive flanges from rotating while I use a tool provided by my technician to pull the output shafts into each drive flange. Once that is done, I'll use my jack to lift and install the differential. The swaybar will be next next because it is easier to install without the muffler in place. Then I'll finish up by installing the muffler with new sealing rings and hardware. At that point, I expect to take it on a brief test drive around the block before I take it for an alignment sometime in the next few days.

Mileage: 193332, Labor: $950, Tools: $30

Friday, June 25, 2010

Rear Suspension Overhaul - Assembly Day Two

When I arrived at the garage I got right to work because I knew I had a very long day ahead. I started with something easy -- securing the shocks to the trailing arm. That uncovered a small wrinkle. As I jacked up the right side trailing arm I noticed that the spring didn't look right. It turned out the lower spring seat on the right side had popped out of the upper control arm and caused the spring to sit crooked. If you look back at yesterday's post you can clearly see that in one of the pictures. Once that was fixed I secured the shocks to the arms and moved on to more pressing (and annoying) things.

When I told my technician about this project initially he smiled and said "Don't curse too much". In spite of dealing with stubborn fasteners, banging my head on various protrusions under the vehicle, and wrestling very heavy objects half way around the state of New Jersey I have managed to maintain my composure throughout the project. In fact, this was a zero curse job...right up the point I started work on the $!#@!$! parking brakes. These infernal things caused me to curse (loudly) several times as I wrestled with the return springs. They were damn near impossible to stretch as required to reach the hole in the adjacent brake shoe. I almost broke one of my hook tools and then decided to try a pair of long nose pliers. With nearly half of my body weight on the pliers I still had a hell of time securing the springs. I managed to get the work done, naturally, but it was the most annoying aspect of the entire project.

The only upside of dealing with the parking brakes -- that is to say, other than the obvious fact that they look great now -- is that I now know how to adjust them. BMW insists that they be adjusted such that the clamping force is matched to within 30% and since they are completely independent of one another that is most certainly a trial and error process. I spent probably 20 minutes just going back and forth between each rear wheel with the parking brake lever in the various states advocated by the TIS to make sure that it was adjusted correctly. I will likely have to tighten them up further after I go through the break-in process but that should be easy enough to do now.

With that nightmare over, I took one of my axle shafts over to my technician so he could assemble the correct components from his wide array of BMW special tools required to pull the axle shafts into the drive flanges. Back home I screwed the shaft onto the end of the axle, inserted the axle into the drive flange, mounted the base to the rotor with a couple wheel bolts, threaded the bearing-equipped nut on the shaft and then used a huge adjustable wrench (also courtesy of my technician) to tighten the nut and pull each axle shaft smartly into its flange.

The right side axle slipped almost all the way into the drive flange by hand but the left side axle barely fit into the flange so the tool was absolutely essential to this task. The lesson learned? Don't think for a second it's possible to just press these things in by hand even with new flanges and remanufactured axles with nice clean splines. The parts are designed to mate with a press fit and special tools are consequently required for the job. Baum Tools makes a tool that should do the job, but it's not as slick (or as expensive, I'm sure) as the BMW toolset. Once both axles were pressed in I returned the tools before anyone missed them and drove back to the garage once again to install the differential.

Due to the angle at which the differential must be inserted into the subframe I found the jack only slightly useful for the task. I wound up hulking the thing up there with my bare hands, and burning out the muscles in my arms in the process. That thing is HEAVY. Once it was in position I mated the input shaft with the driveshaft and then secured the differential with new hardware. I had to use the old nuts to connect the driveshaft to the differential because I forgot to buy new nuts. No matter, really. I have new nuts on order and I have tightened and torque sealed the existing nuts so I can inspect them in the interim to make sure they don't walk before I'm able to replace them with the new parts.

What's torque seal, you ask? It's a colored gel that is used to bridge the gap between a fastener and its mating surface. When torque seal dries it becomes brittle and will crack if the fastener moves. This provides a clear visual indication that the fastener is no longer secure. It can also be used simply to mark fasteners that have been properly torqued and it came in very handy in that sense when I began to secure the axle shafts to the differential. Securing those bolts requires multiple trips between the underside of the vehicle and the interior to alternately secure and release the parking brakes or gear shift so the output shafts can be rotated to provide access to all of the bolts and then secured as required to apply the necessary torque. So my output shafts now look like they belong on an airplane. I can't wait to see if the car lifts off at rotation speed. :)

After about six hours of unrelenting work, I said "uncle" and went home short of my goals for the day. I have eleven hours in the assembly process so far and expect to spend another 2-3 hours tomorrow installing the wheel brakes, swaybar, and muffler. I spoke with the dealer today and they said an alignment might be possible tomorrow but it would be tight. I'm not holding my breath. At this point I think it is more likely to happen early next week.

Mileage: 193332

Saturday, June 26, 2010

Rear Suspension Overhaul - Assembly Day Three

The last day of major assembly began with a minor repair to one of the fasteners on the heat shield that protects the driveshaft. The heat shield had broken free of the fastener so I bought some galvanized fender washers and sandwiched the shield material between them before reinstalling the screw.

Brakes were up next, and it was at this point that I felt most comfortable, since I had done this several times before. Still, installing the brakes took a solid hour and I almost freaked when I couldn't find the little spring clip that holds the brake wear sensor to the inboard pad. A few seconds of deductive reasoning led me to find it left behind on the old brake pad.

I decided to clean the swaybar of a bunch of old, dried cosmoline using some of the Zep degreasing fluid before installing it with new self-locking nuts. That took only a few minutes because I had done that recently too. Interestingly, I found the rubber in the swaybar links riddled with small cracks after only a few years in service. There was nothing I could do about it now, but I may wind up replacing those links again soon.

The muffler turned out to be relatively easy to install in spite of its weight, but I needed to leverage the jack to hold the heavy end of the muffler up so I could mate the pipes with the mid-section smoothly. As per BMW requirements, I used two new sealing rings and new hardware including copper self-locking nuts. There's no getting a torque wrench between the pipes so I fastened them with two box end wrenches (the bolt head is 13mm and the nuts are 12mm...which is a good thing since I don't have two of either size wrenches). They snugged up suddenly and I took that as a sign to stop tightening. Easy enough.

Removing the old (larger) sealing ring left behind on the pipe was as simple as placing a screwdriver on it and hitting the screwdriver with a hammer. The sealing ring is made of some kind of composite material and breaks easily. Graphite appears to be one of the ingredients because my finger tips were a nice shade of dark gray after handling it for only a few moments.

I installed the wheels temporarily (meaning, I did not torque the bolts) lowered the car to the ground and then torqued the axle nuts to 250 Nm (184 ft*lbs). Everyone complains about that torque but I had no problems applying it with my largest torque wrench and my 30mm impact socket. I couldn't stake the wheel nuts with the wheels on because the hub of the wheel got in the way so I jacked the rear up again, removed the wheels, and then staked the nuts before I reinstalled the wheels a final time.

I then lowered the vehicle down on a set of ramps to achieve the normal normal ride height as required to apply a final torque to several fasteners including the bolts that attach the control arms to the subframe and the shocks to the trailing arms. I could not use a torque wrench on the control arm bolts due to clearance issues so I just torqued it by feel. I had sufficient clearance to swing the torque wrench on the shock fasteners, however, so those were torqued to specs without any problems.

With that out of the way, I conducted a last minute inspection before I lowered the vehicle down to solid earth and went to grab the key. The M52 engine can be somewhat finicky when it is started after being dormant but aside from a bit of stumbling on the first few cylinders it fired right up and settled into a smooth idle. And better yet, I saw no warning lights in the gauge cluster. I took this as a sign that it was ready for a test drive and I carefully pulled the car out of the garage for the first time in three weeks.

I got out of the car to conduct another inspection and immediately noticed the rear ride height was a bit higher than before but I expected that given that the new springs hadn't settled yet. I grabbed my cell phone (with my local wrecker's number in the address book just in case) and took the car around the block at normal residential speeds with the windows open to listen for any undue creaks or groans.

At about 25 MPH I conducted some shallow and then progressively more aggressive turns to get the body to roll a bit in an effort to help settle the springs. I also used the emergency brake to stop the vehicle a few times and thus completed the break-in process. Back at the garage I re-checked the ride height and saw it had settled down enough to call it "near normal". I also took into account the fact that the old springs may very well have been sagging a bit. In short, it looks great, and it drives well in spite of not being "officially" aligned yet.

After cleaning up the garage I called it a day after another five hours of work. Tomorrow I'll reinstall the interior and detail it. Then I'll bring it for alignment first thing Monday morning before I call the project complete.

Mileage: 193332, Parts: $5

Monday, June 28, 2010

Rear Suspension Overhaul - Complete

Yesterday I wrapped up the project by installing the interior trunk components, giving it a bath and taking it to the local deli to grab lunch. I tried to arrange for an alignment at the dealer today but as usual they were swamped and without loaners until next Monday so the car returned to duty today anyway. While some might balk at driving a vehicle without an alignment, the reality is the rear isn't as critical as the front and my alignment estimate could hardly be worse than the trailing arms flopping in the breeze as they were prior to the overhaul.

After driving the vehicle over 100 miles since the overhaul the most prominent thing I've noticed about it so far is that I no longer have to constantly countersteer to correct deviations in track caused by the sloppy rear end. The rear end is also more subdued over bumps; it doesn't "bounce" around as much as it used to. And, not surprisingly, the subtle clunks that were caused by the trailing arms hitting the consoles due to the failed trailing arm bushings are gone as well. In short, the rear end hasn't felt this good in years.

If there is any downside to the rear suspension overhaul, it's that the front end now feels sloppy in comparison.

Conclusion

I paid a total of $2922 in parts, farmed out work worth $1480 in parts and labor, bought $445 in new tools, and paid $150 in miscellaneous supplies, for a total of...well, I'll spare you the nickels and dimes and just round it up to $5000. I also saved $800 sourcing parts myself by negotiating higher than normal discounts with my dealer and buying from online vendors.

Research and parts ordering took a good six hours, disassembly required nine hours and reassembly took a solid 15 hours, or a total of 30 hours. I don't know exactly how long it would have taken a professional to do this work, but in all the time I've worked on this vehicle I've typically been within 10% of the book labor figures. If I chop five hours off for good measure and then multiply the remaining 25 hours by the labor rate, I'm looking at a labor "savings" of $2000 for an independent technician (assuming $80/hr) and a cool $3000 if I paid the dealer to do it ($120/hr). I think I'll average those numbers and suggest I saved $2500 in labor. That works out to $100/hr, which is, coincidentally, the number I typically need in order to justify working on the car myself.

In summary, the project cost almost twice what I expected and took three times as long to complete, although much of that time was spent waiting for subs to complete their work. I'm very happy with the result, not only from the perspective of vehicle performance, but also in how much I learned during the process. If you're wondering whether I'd do it all over again, I'd say yes -- but I'd make damn sure I had a lift and, preferably, a nice climate controlled garage in which to work.

Mileage: 193450

Wednesday, July 7, 2010

Alignment

Last week I made an appointment at the dealer for an alignment simply because I got the last alignment done there, most generic alignment shops don't know how to align BMWs worth a damn, and frankly, I didn't know I had other options. I had resolved to pay the dealer's 2.5 hour ransom for an alignment until I learned that Don did alignments for a lot less using an older (but still quite useful) Hunter 611 alignment system. He said that most people don't think he does alignments because his shop lacks the traditional alignment rack equipped with turntables but as it turns out a full rack is a luxury and not a necessity. When Don agreed to do the job for a far more reasonable price it didn't take much effort on my part to call the dealer and cancel the appointment in favor of a new appointment at Don's shop for today.

I awoke to a weather forecast reminiscent of the past several weekends during which I worked on the vehicle drenched in sweat. Around Noon I arrived at Don's shop with the temperature solidly in 90's and knew this wasn't going to be fun for anyone involved. They had fans running in the shop, but as Don pointed out, in 95+ degree heat they feel like hair dryers. After waiting a few minutes for Don to stop cursing at the electrical system on a restored early 70's Jaguar he was working on, he pulled the E36 in and got to work.

If you've ever watched what happens to a suspension under load, you probably know instinctively that the specifications BMW supplies for camber, caster, and toe must be taken at a certain reference point. That reference point is the height of the fender well above the ground, which implies a specific degree of compression in the suspension. That, in turn, is set by loading the vehicle with lead weight, sandbags, dead hookers, old batteries, or whatever else might be lying around.

After Don loaded the vehicle appropriately, he raised it to chest height to install and calibrate each wheel sensor. Then he raised the vehicle as required to loosen the RTAB consoles and tie rod adjustment stop-nuts, at which point I took the opportunity to take a picture of the completed rear suspension overhaul I could not achieve with the vehicle on jack stands due to the limited sight distance.

My picture taking session was soon interrupted by Don muttering obscenities. The stop-nuts were frozen on both sides and no amount of penetrating fluid seemed to make a difference. So Don asked his tech to bring over the big guns -- an oxyacetylene torch. If you work on cars long enough you learn the law of maintenance: what cannot be fixed with a hammer can often be addressed with a bigger hammer, and failing that, heat. While Don grabbed the adjustment flats on the tie rod, his tech applied the flame to the area around the stop nuts. This caused the penetrating fluid to turn to flame, smoke and steam, and that ultimately dissolved the rust and freed the nuts. The car was then lowered onto some stands equipped with turntables to begin the adjustment process.

At this point, I got to take a look at the "before" alignment of the rear. Surprisingly, what I thought was a safe "toe in" estimate turned out to be about -0.3 degrees of toe (toe OUT) on each side. While the rear felt "locked down" in a way I hadn't experienced in years, this explains why it felt "eager" to turn in an unsettling way. As with all alignment specifications, there is an acceptable range of values, and BMW's minimum toe value is +0.05 degrees. Translated: no toe out. Of course, we're only talking fractions of a degree, but the point to take home here is that it doesn't take much to change the character of the vehicle.

The spec for rear camber on the sport package suspension is -2.3 degrees. Higher amounts of negative camber will help keep the rear locked down (lessen oversteer) at the expense of increased tire wear on the inside edge. I think BMW takes that to an extreme so we dialed a bit of camber out and left it at around -1.85 degrees. Toe is nothing to play with, however, so after using a screwdriver to nudge the RTAB consoles into spec he snugged those down and moved on to the front.

The perk about the rear end of the E36 is that it's adjustable to a small extent in both camber and toe. The stock front end, however, is only adjustable in toe. Caster and camber are fixed and based on the structure of the shock towers and the other suspension components. If one's intent is to maintain stock suspension geometry that doesn't sound like a big deal until you realize that the strut towers bend over time and don't always take kindly to the pounding of potholes. As it turns out, my right side caster is just out of specification and, perhaps more importantly, differs from the left by about 0.12 degrees. Camber is within spec on both sides, but different side to side as well.

How much these discrepancies affect the real-world handling of the vehicle is up for grabs, but the only way to fix them is to use caster/camber plates to make both caster and camber adjustable. The anal retentive German in me suggests that this might be something to address in the upcoming front end overhaul.

Mileage: 193850, Labor: $150

Friday, July 9, 2010

Oil Service and Analysis

(Image: ) Last weekend I conducted another oil service after 4372 miles in service and took a sample to send to Blackstone Labs for analysis. Today I received the analysis and breathed a sigh of relief when the report indicated that lead had dropped to 8 PPM. This isn't quite back to the baseline of 4 PPM yet but any drop in wear metals is a good thing. This means I can put off plans to pull the engine and instead focus on other things including overhauling the accessory section and the front suspension.

Front Suspension Overhaul Plans

And while I'm on the topic of the front suspension overhaul, I figured I'd point out what I plan to do:

Many consider a Z3 steering rack upgrade to be a worthwhile place to spend money, particularly for cars that see track duty, but I'm not sure the benefits outweigh the substantial costs in my case. I'd have to purchase the rack outright since I don't have an identical core, and that would translate into something in the neighborhood of $750. Too rich for my blood right now, but perhaps I'll change my mind once I get into the job.

Mileage: 194050 [Oil Service at 193678], Parts: $45, Labor: $25

Saturday, July 17, 2010

Sagging Headliner

You've heard the phrase “when it rains, it pours”, right? And, no, I'm not referring to the three inches of rain we received earlier this week after a good six weeks with not so much as a trickle.

While craning my neck during the morning commute something about the headliner in the vicinity of the passenger side window caught my eye. I did a double take and realized that I had finally fallen victim of the dreaded sagging headliner problem. A closer look when I arrived at work revealed a good 30% of the headliner fabric has detached.

So now I have to add a headliner replacement to the long list of work I have planned for the car. Removing the headliner requires removal of the A, B, and C pillar trims and in order to remove the C pillar trim I have to remove the rear deck cover. As the vehicle has spent the better part of its life as a daily driver sitting out in the company parking lot under the blazing sun the cover is bleached nearly white. That means if I remove it I'd be stupid not to replace it.

Of course, if I'm pulling all the interior trim surrounding the rear window, that would be the ideal time to replace the back window to fix a couple of inoperative defrosting circuits that are conveniently in my line of sight through the rear view mirror and replace the exterior trim that has been hardening and distintegrating for years.

Removal of the headliner also requires removal of the door weatherstripping. I have wanted to replace that for many years but was always put off by its cost. When I last priced the parts a couple years ago each piece retailed for around $250. Now I wished I'd sucked it up and bought the parts back then, as the current price is (put your hands over your ears if cursing offends you), F$#!@! $375 each. My cost is a bit lower but it's still $600 for a couple pieces of weatherstripping. That is highway robbery by any stretch of the imagination, and this is coming from someone conditioned to aircraft parts prices.

As "luck" would have it, replacement of the deteriorating exterior shadowline window trim (the metal piece that surrounds the side windows and formed to fit the famous Hofmeister kink) also requires removal of the door weatherstripping, so it appears I'll be doing the shadowline trim as well. Fortunately those trim pieces are still relatively inexpensive at $35 each. And good thing too -- from what I'm told, they are very easy to bend during installation, and if that happens they go in the circular file.

One thing I have yet to figure out is how to get the headliner out of the interior without destroying it or anything else. Some suggest that reclining the seats is sufficient to provide the necessary clearance while others suggest the seats need to be removed entirely. If I remove the seats it will be hard not to rebuild them, but that's to be expected since I appear to have a thing for slippery slopes.

Mileage: 194378

Wednesday, July 21, 2010

Battery Failure

The day began like any other. I walked out to the car, hopped in, and turned the key. Except this time the car didn't start. No slow spin of the starter. Not even a solenoid click. Just one key chime and the faint glow of a few annunciator lights that reminded me of the last scene in an Airwolf episode called Moffett's Ghost. "Hmmm", I said in my usual sarcastic inner voice, "this one is going to be hard to diagnose."

Normally I'd be well set to handle a situation like this but suffice it to say that my current living arrangements are less than ideal, with my backup car, backup battery (the one I pulled out of the car three years ago) and virtually all of my tools at another location. I did have a volt-ohm-meter (VOM) on hand so I checked the battery and found it at 10.9 volts. Now all I needed to do was determine WHY the battery was discharged.

The vehicle has been starting well and gave no indications of a charging system failure on the drive home the prior evening. I also didn't do anything stupid like leave the lights on overnight and the car is not equipped with an alarm. That meant either some silent accessory in the vehicle was drawing power and pulled the battery under or a cell reversed and the battery was toast. Based on the fact that the battery did not turn over the starter and did not "recover" with the key off as most discharged batteries will, instinct told me it was time for a new battery. Since the E36 is fairly "old school" and more tolerant of a defective battery than the newer vehicles I figured I'd call a local tow company to try a jump start then drive the car over to my garage to get the E46 that I could then use to get the new battery.

When the tow truck arrived the driver connected a 20 foot jumper cable between a jack on the truck and the battery. After a few minutes of charging the starter reluctantly turned over the engine and it settled into a smooth idle. I let the engine idle for ten minutes while the driver wrote up the paperwork and I continued troubleshooting. I put the VOM on the battery terminals and found the voltage at 13.9. This meant that there was enough juice in the battery to energize the field and that the alternator was capable of producing a high enough voltage to run the car's electronics. This increased the likelihood that the battery was at fault and hinted it would be okay to drive the vehicle the few miles necessary to reach my garage.

When I arrived at the garage I strategically parked the vehicle knowing full well that the battery likely wouldn't start the engine again. Needless to say, I wasn't surprised when I shut the car off and then turned the key again, only to be greeted by a sickly rapid key chime -- a tell-tale sign that the vehicle's systems were not receiving full voltage. Since the 15 minute drive would have sufficiently recharged an otherwise healthy battery, this confirmed the diagnosis of a reversed cell.

I got out out of the car, grabbed a 13mm shallow socket and small ratchet, and removed the battery ground terminal followed by the positive. Then I used a 10mm deep socket and 3" extension to remove the retaining bolt, pulled the battery out and plopped it into the trunk of the E46. I then drove over to my dealer and picked up a new battery for $111. Of course my technician saw me waiting at the parts counter (again), feigned surprise, and asked me "Hey, where's your uniform? You're here all the time...you might as well wear one!"

This evening I stopped at the garage on the way home from work and installed the new battery. The vehicle started enthusiastically so the battery appears to have been the problem. However, because I'm skeptical by nature I brought the backup battery, the tools necessary to swap it, and my high current battery charger home with me just in case history repeats itself tomorrow morning.

Conclusion

I have replaced the battery twice over the life of the vehicle. The original battery was replaced in my first maintenance binge back in June of 2002 when the vehicle was a bit over four years old. That battery, in turn, was replaced back in September 2007 in accordance with my maintenance schedule when it had been in service for five years. The core charge on the battery was only $5 so I kept the 2002 unit as a spare and keep it topped off with a Battery Tender.

I don't know why the 2007 unit failed prematurely but my guess is, like everything else, general manufacturing quality has dropped in order to help BMW's bottom line. BMW batteries were once supplied by Douglas (not me) and in 2006 they switched to Exide. The battery I installed in 2007 was therefore an Exide unit though I don't recall seeing an Exide brand on it. The new battery I installed today has the Exide name prominently displayed on the label.

The general consensus online seems to suggest that Douglas made good batteries and Exide quality is not up to par with the Douglas. Still others have suggested that Exide simply bought the Douglas factory so the batteries are made to the same standard of quality. In any case I can't make a judgment based on a single event but I won't be surprised if the new Exide unit fails in under three years. If it does I'll change my maintenance schedule at that time to reflect the new reality.

Most dealers, incidentally, get $90 to install a battery and of course they charge full retail for the battery which is $140. That means I saved $90 in labor and about $30 in parts doing this job myself.

Mileage: 194515, Labor: $75, Parts $111, Parts Saved: $29, Labor Saved: $90

Friday, July 23, 2010

Remaining Parts for Accessory Overhaul

The remaining parts needed for the accessory overhaul arrived today. I bought the parts from the local dealer primarily because I wanted to simplify handling of the core charge refunds. The dealer's parts guys were kind enough to extend a 20% discount to me so the alternator cost $471 ($589 retail) while the power steering pump cost $333 ($417 retail). I also picked up a few extra fasteners I neglected to pick up in the last Tischer order for around $6, which brought the total to $810. I also paid core charges of $50 for the alternator and $60 for the pump but I'll naturally get those back when I return the cores after the work is complete.

While the ETK indicates only the power steering pump is remanufactured, as the pictures show the alternator is remanufactured as well. I have heard stories about the relative quality of Bosch rebuilds and one site went so far as to disassemble an Bosch overhauled alternator to find it equipped with cheap Chinese bearings. Will I get the same lifespan out of this remanufactured alternator? Time will tell. Fortunately the rebuilt pump looks as good as new and feels like it should go the distance.

You may note that the alternator does not come with a pulley. This means I'll need to swap the pulley from the old unit using my air ratchet. The power steering pulley is, of course, being replaced with a new aftermarket aluminum unit as shown. After checking the fit of the new pulley on the pump the plastic pulley I bought earlier from the dealer was returned for credit.

Mileage: 194575, Parts: $810, Parts Saved: $202

Sunday, July 25, 2010

Accessory Overhaul Day One

I got a late start today because I just couldn't fathom the idea of getting up early on my birthday. The weather forecast also promised 90+ degrees with high humidity so I was not exactly rushing out the door to work on the car if you know what I mean.

In any case, I got to work around 1:30 and managed to accomplish the following before leaving at 7PM:

I had originally planned to do an "official" power steering flush as part of this work but quickly ruled that out because I didn't want to waste any more time trying to acquire the necessary fittings. Fortunately, the ATF that I purged from the rack was still in very good shape so I know I won't be doing the new pump any harm by swapping 90% of the fluid again. Truth be told, this is exactly the way a technician would do it.

Even after I drained the radiator, when I removed the water pump a bunch of coolant flowed out of the block. I was expecting some coolant but not that much. Needless to say I didn't have a drain pan underneath the car at the time and covered the floor in coolant. I hosed the floor down and then got back to work.

Believe it or not, until now I had never removed the air conditioning belt so I didn't know exactly how to de-tension the belt because it is equipped with a different tensioner (hydraulic) than the mechanical tensioner I've worked with before. I figured it out pretty quickly, however. Both belts were showing their age and definitely needed to be replaced. Mike Miller of the BMWCCA has more than once recommended 60K as a proper service interval for good quality serpentine belts. Crappy belts on the other hand, might not last as long, so that's why it's important to check them at least once a month.

I was somewhat confused about how to remove the power steering pump, as the new pump was assembled in such a way that it appeared to require only two long bolts to install it, but as it turns out it is installed using a total of four bolts, including two bolts accessible from the rear of the assembly. Oddly enough, one of the brackets provided with the new unit will have to be removed from the pump to install it.

The oil filter housing gasket was very hard and remained stuck to the block when I removed the housing. I carefully peeled the gasket from the block and then used some duct tape (the only thing I could get to stick) to close off the oil passages before spraying everything down with a can of brake cleaner. This wasn't the least expensive or the most environmentally friendly way to do this but I needed a stream of degreasing agent under pressure and this did the job. For whatever reason I don't yet have a compressed air cleaning wand in my tools arsenal that I could use to spray a more friendly degreasing agent (like the ZEP citrus stuff) but I plan to buy one soon.

I had some difficulty finding a torque spec for the six bolts that hold the oil filter housing to the block. I did find an obtuse reference in the TIS for 40Nm and that's probably safe for a cast iron block, but generally speaking most of the block fasteners have relatively low torque specs in the neighborhood of 25 Nm (18 ft*lbs) so I went the conservative route and torqued to 30 Nm (22 ft*lbs). I think this will be acceptable because I could feel the housing pivoting over the gasket so I knew it was doing its job. Whatever the torque spec, the key to installing the housing correctly is to evenly torque the bolts so the housing mates evenly with the block. I had to use a 12" extension and a deep 13mm socket to torque the bolts.

I'm still on vacation tomorrow and plan to finish the work then. So far I have about four hours in the job. I took several breaks and was forced to sit on my hands for about 45 minutes while I waited for a strong line of thunderstorms to pass, but I have to admit it was nice just to relax for a change and listen to the soothing sounds of wind, rain, and thunder.

Mileage: 194600

Monday, July 26, 2010

Accessory Overhaul Complete

I got up at a reasonable hour today so I managed to start work at around 11 AM and finish up around 5PM. I took almost an hour for lunch and had to run an errand in that time so that means I spent around four hours doing the following:

When I flushed the power steering system yesterday I took extra time to rotate the wheels back and forth until I could no longer feel resistance or hear fluid squishing in the system. This purged the maximum amount of fluid possible using the optimal flush method. When I filled it today I moved the wheels back and forth (actually by grabbing the spokes in the rim and pivoting the tire rather than the steering wheel) until I felt consistent resistance in the wheels. All told the system took almost a quart of fluid. After the test run the fluid was not translucent, but I wasn't expecting it to be as only the official flush method has any hope of flushing all the old fluid and particulates from the system. I plan to do that at some point in the future but as I said yesterday I couldn't justify the time at this point.

My technician originally told me that remanufactured alternators come with a pulley attached. The remanufactured unit I received from the dealer most certainly did not come with a pulley so I had to transfer the pulley to the new alternator. I made quick work of loosening the pulley nut with my air wrench and a 24 mm thinwall socket and I was able to pull the pulley off the shaft of the old alternator by hand without significant effort. Oddly, the very same pulley would not fit with mere hand pressure onto the shaft of the new alternator so I had to use a 22 mm impact socket as a drift and hammer the pulley onto the shaft. Mind you this was not a crude attempt to fit a square peg in a round hole...the pulley clearly fit the shaft...it was simply a press fit. After I installed the pulley I glanced skyward and said a small prayer that the new alternator was not defective because I didn't have the foggiest idea how I would remove the pulley from the shaft and transfer it back to the old alternator. If I ever do this job again I'll buy a spare pulley just in case.

I would have preassembled the engine driven fan and new clutch ahead of time to save a few minutes but I was not sure of the orientation. It is entirely possible to mate the fan to the clutch in several ways. For clearance reasons I had to be sure, so I just waited until I could examine the old unit more closely and use it as a template. Since I've removed and reinstalled the fan several times in the past I made quick work of installing it this time and took a minute to bask in the glow of a nice new clutch and fan assembly.

Incidentally, after a test drive I opened the hood and noticed that the engine driven fan was spinning and blowing air at a rate I hadn't seen in, well, a long time. This tells me that the original clutch was near or at end of life. After all, the viscous coupling is supposed to become rigid when the temperature increases and therefore turn the fan at the speed of the water pump, and I was clearly not used to seeing it blow this much air. So the lesson learned is these things do go bad and not necessarily in an obvious way. The corollary is that the engine driven fan serves a purpose on these cars and should not be removed, at least on vehicles that came equipped with them from the factory (not all did).

I always keep a gallon of 50/50 mixed coolant around just to top off the system when necessary. When I used the entire gallon I had on hand and realized the system wanted more I had to run out for some coolant and distilled water. That ate up a solid hour of the day but it was necessary because all told the system took nearly two gallons. This means I can count this as a coolant flush in my maintenance schedule. Fortunately I had no issues with the cooling system bleeding process, but this was likely because I left the front end jacked up for the first few minutes of engine operation.

A few weeks ago I was hanging out at Don's shop and saw first hand how the bleeding process can go awry. I stood silently to the side as he and one of his techs lit up a freshly overhauled S52 on a track-prepped M3. The tech began to add coolant and Don started the engine. To help circulate the coolant and free any air from the system he revved the engine between 4000 and 5000 RPM and watched the temperature needle (aftermarket VDO unit) like a hawk. When the needle started to rise above a safe point he took this as a sign that an air bubble had formed in the system and the pump was not circulating coolant as required. To remedy the problem they quickly put the front end of the vehicle on the lift and raised it to aid the bleeding process. As expected this cleared the air bubble and the temperature dropped to the regulated value. Lesson learned: the more coolant you remove from the system, the more you risk encountering problems during the bleed, and the more you have to be on your guard with respect to monitoring coolant temperature.

When everything was ready to go I verified all fluid levels and then applied a VOM to the battery terminals to make sure the system was charging. The charging voltage of 14.0 volts, while slightly higher than usual, was within the normal range. A short test drive around the block confirmed that the infamous power steering whirring noise that had plagued the car for years is gone. Once back at the garage I jacked up the front end again to conduct an inspection. I found no leaks or other problems so I put it back on the ground, pulled it out the garage, washed it for good measure and called the project complete.

Total project time was eight hours. I have no idea what the dealer would charge but something tells me that book labor, with each task taken separately as it usually is, would easily be in the vicinity of 6-8 hours. Multiplying the lower figure by $128 (my dealer's labor rate) equates to $768 so I think I can safely call that the labor saved doing this job myself. The parts came to a total of $1325. I saved $290 sourcing parts myself, so that brings the DIY dividend on this project to $1058. Not bad for a couple days work, doncha think?

Mileage: 194662, Labor Saved: $768

Sunday, August 29, 2010

Front Brakes

The last few times I washed the car I noticed concentric grooves in the front right rotor, which is caused by the pad wearing down to the level of the rivets that fasten the pad to the backing plate. The brake wear indicator is on the left front and hadn't tripped but a cursory inspection of the pad thickness on both sides convinced me it was time to do a brake job. I ordered OE pads, rotors, and a wear sensor just in case I got to the job after it tripped. The parts came in on Friday and I performed the work today.

(Image: E36 in the detached garage getting front brakes installed)All in all this was a standard front brake job. I did notice some asymmetry in the wear patterns, however. The right side pads were worn more than the left, and the outer right side pad was worn down to the thickness of a quarter. Had that pad been monitored by a sensor it would have tripped at least 500 miles ago. I'm not sure why the right front pads took more of a beating than the left, but it may have something to do with a sticky caliper. This hints at a need to overhaul the calipers during the upcoming front end overhaul. This will naturally add some cost to the job, but since I had plans to install new brake lines on the front during the overhaul anyway I won't incur any additional labor.

I took a bit more time to clean up the caliper carrier brackets in a bucket filled with water and some of the same citrus degreaser I used during the rear suspension overhaul. Even after I scrubbed with the bristle brush I noticed that some of the gunk (technical term for dried grease and brake dust) simply would not come off unless I attacked it with a small wire brush. BMW specifically recommends against doing that for some reason, but I used a brass brush and went easy on it. I let the parts dry in the sun and then applied a new coating of high temperature grease to the areas where the pads ride in the bracket. Of course, I also applied grease to the tabs of each pad as recommended by BMW during the installation process.

The bonus of the day was that I managed to save the existing wear sensor. The thickest of the four pads I removed just happened to be on the inner left side (the one with the sensor) and the pad was just above the thickness that would have started sensor wear. Since there's no sense in replacing an otherwise intact sensor I just cleaned it up with a rag and reinstalled it. I bought the part anyway so this technically didn't save me any money this time around but it will in the long haul. The sensor is only $12, but that's better in my pocket than anywhere else, especially in this economy.

As I've said more than once, brake jobs are a great place to save money because they are performed relatively frequently and are quite expensive at the dealer. Book labor is 2.0 hours per axle so I saved $128 * 2 or $256 doing this job myself. My discounts from Ticher also saved 20% of the parts cost or $58. This brings the DIY dividend to $314. I'm normally able to do this job in under two hours but I took some extra time to degrease the parts so I managed 2+15 on the clock. That works out to $142 per hour, which is far in excess of the $100/hr I usually need to justify working on the car myself. Not a bad way to spend a few hours, wouldn't you say?

The last front brake job was done at 165475, which means this set lasted 30795 miles. Had I waited until the sensor tripped I probably could have crossed over 31K miles but I'm very happy with anything over 30K.

Mileage: 196270, Parts: $228, Labor Saved: $256, Parts Saved: $58

Saturday, October 9, 2010

Oil Service and Analysis

Last Saturday I ran through a quick calculation and realized I was coming up on 4300 miles so I decided it was time for an oil service. I picked up six quarts of 5W-30 at the dealer and completed a mid-cycle oil service on Sunday. I didn't get around to sending the oil kit in for analysis this week so I won't have the data until later in the week but I expect this analysis will give me the information I need to put the lead wear problem to rest and go back to doing analysis every other oil service.

And not a moment too soon since Blackstone just raised their analysis from $22.50 (already the highest in the industry) to $25. I suspect this is a response to lower sales, as preventative maintenance practices are usually the first to go when the bottom line is under attack, but raising prices in a deflationary environment is akin to kicking the customer in the nads when he's down. If it goes up again anytime soon I'm definitely going to look elsewhere for analysis services. They don't have the lock on that market, that's for sure.

Replacement Style 30 Wheel

When I removed the snow tires back in April I set them up along the garage door so I could clean them before I put them away for the season. Unfortunately, I left one of the wheels perched in a precarious spot and accidentally kicked it as I was coming out of the garage. It fell face down into the stone driveway and that managed to put deep gouges in the metal and generally destroy the finish. I was not exactly motivated to deal with the problem at the time so I just stacked the wheels in the garage and walked away.

Unfortunately, the Pilot Sport A/S Plus have not worn nearly as well as the Pilot Sport A/S, which is really saying something since the regular A/S were not exactly known for longevity. The rears have been at the wear bars for the last month or so I need to switch to my snow tire set on schedule at the beginning of November. This implies having the set ready to go by the end of the month so late this week I placed an order with Tischer for a new 16" Style 30 wheel for $210. While I didn't want to spend that money I considered myself lucky when I clicked "submit" on the order because most BMW wheels (even legacy parts) are twice that price.

I also ordered 10 new rubber valve stems, valves, and metal caps for $47 because I can no longer trust my dealer to stock valve stems for these old-school, non run-flat tires. Five of the stems will be used to eventually replace all the stems on the winter set while the other five will replace the trouble-prone metal stems in the CSLs.

The parts should be here later this week, at which point I'll need to have my technician swap them. Had the local independent tire place not trashed the finish on one of my CSL reps earlier this year I would have given them the job and saved a few bucks in the process, but it appears I'll have to pay the dealer $40 to protect the finish of my wheels from now on.

Cluster Odometer LCD Segment Intermittent

A couple months ago I noticed that the right-most two segments of the trip odometer digit display occasionally fail to work. It's a purely cosmetic failure but annoying nonetheless. The only fix for that is a new cluster ($675) plus coding at the dealer.

I'd normally live with such a minor malfunction, but the cluster has had another more annoying characteristic for some time: uneven backlighting on the face of the speedometer and tachometer due to delamination of the gauge overlay. I read an article on one of the forums years ago that explained how to disassemble the cluster and reinstall the overlay using a special 3M adhesive but I never had the time or inclination do that. And it's probably just as well at this point.

I have yet to ask my technician whether it is possible to R&R the cluster and then drive the vehicle so I can do the work myself and drive it to the dealer for coding, but in the event I can't do that I may just do the work myself anyway and put it on a flatbed. Surely that will cost less than book labor at $128/hr, right?

Future Plans

My savings account took quite a beating this year addressing the rear suspension and accessory overhauls so I decided to postone the front suspension overhaul until the spring.

Unless something unexpected comes up I'm done spending money on the vehicle this year. The only thing I may do before winter sets in is replace the glass on both side mirrors due to delamination and a failure of the heating elements. I'm not exactly looking forward to spending in the neighborhood of $55 for each part but like the heated washer nozzles I repaired last winter the mirror heating elements do serve a useful purpose in snowy weather.

Let's just hope we don't have another winter like last year. If that happens I may just move to Florida.

Mileage: 197986, Parts: $55, Parts Saved: $15

Thursday, October 14, 2010

Oil Analysis Results

(Image: Blackstone Labs Oil Analysis Report for October 14, 2010)Blackstone returned the oil analysis results today and I have officially breathed a sigh of relief because the lead value has returned to normal. This leads credence to the diagnosis of a particle streak and gives me hope that this engine could soldier on for another 50K miles or more without needing any serious work. The downside is, as I approach 200K miles, that if I do experience any trouble with the engine the best course of action will likely be a complete teardown and rebuild...probably to the tune of $10K. All I can do is hope that by continuing to service the engine properly it will go the remaining distance.

Years ago when I started hanging around my technician's shop I noticed he used to remove the engine air filter and tap it on a clean surface. When I saw the amount of sand and other debris come out of the pleats I vowed to perform that simple task on a regular basis (every couple thousand miles, or every oil service at a minimum) and I'm firmly convinced that this practice, in combination with a new filter every 30K miles, has a positive effect on the silicon value in these results. I've said it before, but I'll say it again. I have no idea why anyone would want to run a so-called "high performance" filter and risk sandblasting the interior of their engine.

Email Trend

I figure I'll take this time to point out a trend in the email I've been receiving over the last couple of years.

I still receive the usual "thanks for the site" email a few times a week and always appreciate those because it tells me people are still getting something useful from this site, but I've noticed a disturbing increase in the number of emails I receive from people asking advice on how to circumvent proper maintenance procedures for one reason or another (usually the cost involved). A couple cases in point:

More than one person has asked me for advice regarding alternatives to replacement of the auxilliary fan. When I reminded one guy that the aftermarket unit highlighted in my Auxillary Fan DIY was a bargain relative to the OE part and a great way to save money, he openly admitted that he didn't have $250 for that part. As I tried to come up with a rebuttal I just shook my head and wondered WHY.

One guy from a foreign country that will go nameless recently asked me if I would comment on how the engine would run if he removed the O2 sensors and gutted the catalytic converters because "he couldn't afford $2000 cats on a car I bought for $3000". Regardless of the fact that his country reportedly had no regulations prohibiting this modification, I had to be blatantly honest and tell him that not only would that result in decreased engine performance but also a hell of a lot more pollution. I won't bother you with the remaining details of the exchange but this was the proverbial straw. I have to get some things off my chest:

  1. Please do not send me email asking me how to cut corners on maintenance. This website should be proof positive that I subscribe to a different philosophy so I will no longer waste my time trying to give any advice contrary to that philosophy.
  2. Just because you bought your BMW for $3000 does not mean you can afford to own it. I spend, on average, $0.25 per mile on maintenance on my E36. Do the math before you sign on the dotted!
  3. If you can't afford to spend $2000 for new cats it's time to buy a Honda, and if you don't have $250 to allocate to vehicle expenses in any given month it's time to acquaint yourself with alternate forms of transportation including public transit and/or a bicycle.

And before you email me to cry foul, keep in mind that I practice what I preach. I've long wanted to purchase a twin engine airplane, and at market prices approaching that of a nice Porsche, I could buy one if I wanted to, but I haven't taken the leap for one reason: I can't afford to feed the thing 30 gallons of 100 octane aviation gasoline per hour when gas is $5/gallon. That's $150/hr in fuel alone, and fuel is but one small cost of the total operating expenses of such an aircraft. The same could be said for a BMW.

Mileage: 198500, Parts: $25

Saturday, October 23, 2010

Snow Tire Remounted on Refinished Style 30 Wheel

Earlier this week I received my latest order from Tischer but when I first saw the tiny envelope that arrived I figured either Tischer had developed a groundbreaking way to compress aluminum wheels for shipping purposes or they neglected to include the wheel I ordered. The enclosed invoice clearly listed the wheel as one of the line items and I was charged for it yet it was nowhere in sight. Later that day I sent an email to Jason and he eventually replied to tell me that 1) as it turns out the Style 30 wheel is no longer available from BMW and 2) his people screwed up and should not have completed the order and charged me for something that did not ship. He promised to issue a credit for the missing wheel so I really didn't give the billing error another thought.

I did, however, begin to mull over what to do given that I still needed a replacement Style 30 wheel. I recalled speaking with the guys at Wheel Collision Center, a wheel refinishing shop near Allentown, PA some time ago so I browsed their website for a Style 30 wheel and called them to discuss my options.

(Image: Refurbished style 30 wheel remounted on Dunlop Winter Sport M3)The guy who answered the phone was helpful. He quickly pointed out that they had a few of those wheels in stock and could refinish and deliver one for me in 3-4 business days. He offered to sell me a refinished wheel outright for $185 or an exchange for $155. Always out for a bargin I decided to purchase the wheel in exchange, in which case they would send me the refinished wheel out of their stock, charge me the outright price, and the issue a $30 credit when they received the damaged wheel in the same box. After $20 in shipping costs plus tax I wound up with a bill for $220, $10 more than the price I would have paid BMW for a new wheel, but actually $20 cheaper overall than I would have paid Tischer to ship the new one to me. So I was ahead of the game at this point, if only by a few dollars.

The wheel arrived Thursday so I drove it and the damaged wheel over to my dealer technician Friday morning. I explained what I needed and told him that there was no rush. When I asked him what service advisor I should see to square up he said "don't worry about it...you buy enough stuff around here!". While my bank account can certainly attest to that statement I don't expect anyone to do work for me for free, yet he offered just the same. I think that says a lot about how important it is to develop a good relationship with your local BMW technician, or for that matter, good relationships with good people in general. I thanked him for the gesture, wished him a good weekend and ducked out the door on my way to work.

After running a few errands I picked up the newly mounted tire today and it looks great. In fact, that's the problem. The guy at Wheel Collision kindly warned me about how much nicer the new wheel would look in comparison to the old so I knew this going in, but the unintended consequence of this work is that I've decided to keep my old wheel for now and drive the entire set to Wheel Collision in the spring so they can straighten, refinish and color match them. After all, Style 30's are no longer available so I have an added incentive to keep them in great shape.

Check Engine Light

While on the way to the dealer today the Check Engine light illuminated again. I was cruising with the sunroof open and began to smell gasoline as I slowed to a stop at each traffic light. My diagnostic subroutine kicked in and I quickly deduced that because the engine was running smoothly and the fuel gauge wasn't dropping quickly I figured I didn't have a massive fuel leak, so I decided to continue the last ten miles to the dealer and have them look at it.

Upon arrival I asked one of the techs if he could pull the codes. He attached the latest version of the BMW diagnostic computer (Software Service Station, or SSS) and started a full read of all modules. He then instinctually walked over to the gas cap and removed it and showed me where one part of the gasket was more wet than the surrounding area. And then it dawned on me. Sure enough, I had filled up the tank the prior night, the moron at the station evidently failed to reseat the cap properly (again) and the pressurized gas vapor was leaking through the seal, condensing to some extent. The end result: a fuel system leak and a Check Engine light.

The SSS seemed to take forever and a day to complete its scan (certainly longer than the GT1 it replaced) but it eventually confirmed the fuel system leak. The tech then issued the command to reset all codes, reinstalled the gas cap and I was back on my way.

This experience has highlighted two things:

  1. The IQ and/or attentiveness of gas station attendants continues to drop and I didn't think that was physically possible. I suppose the only way to prevent this is to double-check the cap on all future fill-up or perhaps move to a state where the gubmint deems me smart enough to fuel my own vehicle.
  2. I need to buy a diagnostic solution like AutoEnginuity so I can begin to do more diagnostics work myself. At $500 for the BMW-specific package plus the cost of a laptop it's an expensive tool but no less important than anything else in my toolbox.

The Typical BMW Buyer

While my car sat outside one of the bays connected to the SSS, a couple in their 40's pulled up in the monstrosity more commonly known as the X5. They quickly managed to divert the attention of the tech helping me to tell him that they were experiencing a possible leak in one of the tires. They admitted that the left rear tire was "making noise" and they stopped a few miles up the road to fill it up, but that the tire pressure monitoring (TPM) system was still complaining.

I didn't catch the entire conversation that ensued between the tech and this couple, but the gist appeared to involve a complaint about how the TPM system worked. My ear perked up, however, when the woman concluded one of her points with the observation that this was a "fifty thousand dollar vehicle". Now pretending to be distracted with my own car I couldn't help but roll my eyes in disbelief that these two rocket scientists believed that the TPM system was obviously at fault when it in fact correctly highlighted a persistent loss or differential in tire pressure. These people obviously did not own a tire gauge and therefore did not necessarily fill the low tire up to the correct pressure or check the OTHER tires to make sure they were up to the same pressure.

The technician, obviously experienced in dealing with the moronic masses, diplomatically asked all the right questions, made all the right recommendations, and even offered to put the vehicle up on a lift for free to check for damage to the tire (he found none). I couldn't help but think of the irony here: TPM systems were mandated in this country because lots of stupid useless people bought a bunch of overweight Stupid Useless Vehicles (SUVs), never bothered to check tire pressure, and then had the balls to sue everyone in sight when their tires blew out, the vehicles rolled over and exploded. And yet these are the very same people that complain about the system when it correctly points out the fact that they are not doing even the most basic of maintenance procedures -- checking their tire pressure on a regular basis.

And now, because of what has become the "typical BMW buyer" I can't even buy a new BMW that weighs less than 3000 lbs, lacks a turbocharged engine developing less than 300 horsepower (necessary to haul all that extra weight around and meet magazine friendly performance numbers), gets more then 30 MPG and has a frickin' dipstick to allow me to check my engine and transmission oil quickly and easily. Thanks, morons. Thanks a lot.

Mileage: 199000, Parts: $220, Parts Saved: $20

Sunday, October 31, 2010

Return to Snow Tires

(Image: Closeup of Pilot Sport A/S Plus wear pattern)It's that time of year again so in spite of a blustery fall day with temperatures in the mid 50's (cold considering it was 75 degrees here last weekend), I put the E36 in the garage and swapped the set of spent Pilot Sport A/S Plus for the set of Winter Sport M3 including the refurbished wheel.

This was the first time I'd been under the car since the rear suspension overhaul so I spent some time looking around. Aside from the fact that a light accumulation of dirt had managed to reduce the luster of the new parts, I found everything in good shape. I cleaned all the hubs and applied a new film of anti-sieze before I installed the wheels, torqued the wheel bolts, and pumped the tires up to 32 PSI.

A close inspection of the Pilot Sport A/S revealed significant wear to the inside edges of both rear tires. I've always had pretty even wear on the rear tires of this car in spite of an alignment involving two degrees of negative camber so I can only assume that this was due to scuffing as a result of the misalignment in toe caused by the failed trailing arm bushings. And surprise, surprise. The left side was worn to a greater degree than the right, which is consistent with the fact that the left side bushing failed first.

MPG Trend

(Image: Out for lunch one crisp fall day with the snow tires mounted)As regular readers may recall I record some basic data every time I fill the tank including the amount of fuel, cost, and CONSUM1 and CONSUM2 numbers from the OBC. I reset CONSUM1 every time I fill up and never reset CONSUM2, so I wind up with a short and long term average.

The long term average in this vehicle has been remarkably consistent at 24.3 MPG. That was, of course, until I installed the 18" CSL reps back in 2006. Mileage dropped exactly 1 MPG to 23.3 like clockwork, no doubt because the wheels are heavier and the weight is concentrated farther away from the hub. Thus, the engine has to work harder to accelerate the vehicle and some loss of efficiency is expected.

In fact, I was getting 23.3 consistently in April and May of this year. After the rear suspension overhaul, however, I noticed an interesting trend: the mileage kept getting better and returned to 24.3 a couple months after the overhaul. I have never seen it this high while equipped with the CSLs. Since the change in gas formulation occurs around here in April I think I can negate its effects and instead attribute the increase in MPG to a loss of friction in the rear end. Not surprising when you consider that I replaced every moving part back there.

Of course, this is only a theory, and I hope to use the mileage data of the next several months to confirm it. If my theory is correct I expect MPG to increase to roughly 25 MPG while equipped with the smaller 16" wheels.

Mileage: 199283

Thursday, November 18, 2010

Milestone: 200000 Miles

(Image: 200K Miles)

I remember when I was young (you know, back in the Lower Paleolithic period) car odometers only had five digits because they were not expected to last that long. And if you did manage to "roll" the odometer back to 00000 it was seldom something to celebrate because by that time the car was likely rotted out and and ready for the scrap pile.

Today, odometers have six digits, cars are fully expected to last a lot longer than 100K miles and, at least in the eyes of this BMW owner, "rolling" the odometer is an eagerly awaited milestone: even a rite of passage.

I can't quite believe I've owned this car for nearly thirteen years, but as I have long said, a good car is as rare as a good woman, and when you find one, you keep her. And so I shall. Here's to 200K and looking forward to 300K.

Keep 'em running folks!

Mileage: 200000

Sunday, December 5, 2010

Fog Light Bulb Replacement

One of the more annoying aspects of winter in the Northeast is that the days are shorter and I inevitably wind up driving home from work at night. Since the US version of the E36 low beam headlights generally suck I wind up driving with the fog lights on. They are not really designed for long distance illumination, but any additional light brought to bear on a dark country road is always helpful.

In any case, one night last week I realized that the lighting pattern was not symmetrical. It didn't take long to figure out one of the fog light bulbs had burnt out so the following morning I picked up a couple H1 halogen bulbs at the dealer (BMW part number 63-21-7-160-777) and installed them.

The procedure is simple:

  1. Push a long thin screwdriver into the upper hole in the grill adjacent to the fog light to release the fog light assembly. When successful, the inner side of the fog light will pop out as if the fog light is hinged on one side. It is not strictly necessary to unplug the vehicle's wiring from the fog light assembly. Avoid the extra work if possible.
  2. Grasp the reflector assembly in one hand while you use the other to twist the black cylindrical wiring connector counter clockwise until it unlocks (only an eighth of a turn is necessary). Then carefully separate the two components being careful not to stress the short wires.
  3. Grab the insulated terminal that provides power to the bulb and pull it off the bulb. Be careful to grab the actual spade connector and not just its protective rubber boot.
  4. Squeeze the two free ends of the bulb retainer clip together, pushing down as required to free them, then pull the arms up and allow the retainer clip to fold back and out of the way. This will release the bulb.
  5. Pull the old bulb out of the reflector assembly and replace it with a new bulb. Do NOT touch the glass of the new bulb (open the box carefully to figure out what end you're grabbing first) or it will fail prematurely.
  6. Replace the retaining clip and reattach the reflector to the wiring cap, being careful to insure that the orange sealing ring is seated properly in the cap before mating the two components and twisting the cap clockwise to lock it.
  7. Install the fog light assembly by seating the outer portion of the assembly with the vehicle first, and then press the inner portion of the glass to lock the assembly in place.
  8. Just to make sure the installation is secure, alternately push and attempt to pull the assembly out of the bumper. If it doesn't pop free the fog light is installed correctly.
  9. Test the lights. There is no need to start the vehicle to test the fog lights, but remember that the headlight switch must be turned on and the high beams disabled in order for the fog lights to work. Keep testing of lighting to a minimum with the engine off to avoid undue drain on the battery.

The bulb that failed was provided as part of the new ZKW OEM fog light assemblies I installed back in 2007. Even though only one bulb had failed I replaced the pair because I tend to follow the "rule of bulbs", which is to say that in any combination of bulbs that shares the same duty cycle, where one has failed the remainder are sure to follow shortly.

Instrument Cluster Replacement Research

After some searching online and in the TIS, I discovered that the procedure to replace the instrument cluster in the E36 is pretty easy, and should not involve any coding at the dealer, but it does have a catch.

As it turns out the vehicle's mileage is stored, among other places, in the coding plug on the back of the cluster and inside the cluster itself. If the mileage stored inside the cluster does not match that in the coding plug the mileage shown will be whatever was previously stored inside the cluster and the tamper dot will illuminate to indicate the discrepancy.

The BMW TIS documents a procedure to synchronize the mileage stored inside the cluster with the mileage in the coding plug and remove the tamper dot. The catch, of course, is that this procedure only works as intended if the mileage stored in the replacement cluster is lower than that stored in the coding plug.

My current understanding is that new clusters ordered from BMW are set to 0 miles and this procedure will set the value to the current vehicle mileage without any extra coding. If true, that means I can replace the cluster myself and save at least $250 in labor and coding charges.

Mileage: 200700, Parts: $16

Sunday, December 12, 2010

HVAC Controller Gremlins Return

Way back in 2003 I replaced the HVAC controller after it exhibited progressively more frequent symptoms and then failed entirely. At the time I had the dealer diagnose the problem and the solution was predictable: I spent $325 on a new controller and $80 in labor installing and coding it.

Yesterday morning I decided to do some errands so I hopped into the car and turned the key. At that instant I remembered I'd forgotten something in the house so I went back in to get it. Not a minute later I walked back out to the car and stopped in my tracks when I heard the aux fan spin up. Knowing full well that I'd just started the car and the temperature was in the "balmy" 40's I knew engine temperature alone could not explain why the fan was running.

I got in the car and quickly realized that the HVAC controller display backlighting was not functioning. I could barely make out the blower fan speed and tried to adjust it. Nothing happened. I then tried some of the other buttons and realized that those didn't work either. Since I write software for a living and am all too familiar with the three finger salute I turned the car off, waited a few moments, and then restarted it. Not surprisingly, the controller returned to life.

In any case, I'd seen this movie before. If left alone, the problem would likely worsen over the next few weeks and the controller would eventually stop working entirely. That's an inconvenience in warm weather but a serious problem in winter so I let my fingers do some Googling.

A quick check of my parts supplier revealed that the controllers are now $440 and have a $200 core charge. I know the core charge did not exist in 2003 because the dealer gave me the old unit back and I (foolishly) threw it out, thinking at the time that the unit was unrepairable and I would never be in a position to use it in again anyway. After all, who would have guessed I'd keep this thing thirteen years?

Fortunately, this time around I have an arsenal of knowledge available to me. As it turns out the problem is caused by a failing (or failed) capacitor used in the controller's power supply filtering circuitry. There is risk in attempting the repair of course, but as I see it the worst that will happen is I'll have to spring for a new controller and the related coding charges. If I succeed, however, I'll wind up saving at least $500. That's enough of an incentive to leverage my knowledge of electronics as well as my soldering equipment and technique.

The replacement part is on its way from DigiKey and I hope to complete the repair next weekend. Naturally, I plan to thoroughly document the process for the benefit of all.

Mileage: 201100, Parts: $10

Saturday, December 18, 2010

HVAC Controller Fixed

When we last saw our hero, he was facing a grave threat -- freezing his nads off driving down the highway at 80MPH without any heat because of a faulty HVAC controller. We now continue with the story...

The first indication of a problem with the HVAC controller appeared last weekend so I ordered a new capacitor from my electronics supplier in an attempt to do a component level repair on the unit as opposed to throwing the better part of $500 at BMW for a new unit. I knew I could expect intermittent operation of the climate control system and thus intermittent heat until it was fixed, but little did I realize how bad it would get as quickly as it did.

By the drive home on Monday the controller went from working perhaps 95% of the time to working little more than 40% of the time. Whenever the controller would stop working, the "Auto" button LED would continue to be illuminated and I could faintly make out the segments of the fan speed indication on the display, but no control on the unit worked, the HVAC blower motor did not run, and the servo motors that automatically control the inner and outer doors remained silent. No degree of menacing looks or threats of physical violence with a clenched fist helped matters. Even a few well-placed bitch slaps on the nearby dashboard structure did not convince the unit to behave. It turned on and off with no apparent rhyme or reason.

(Image: Closeup of capacitor changed to fix hvac controller) While dealing with this headache I discovered a couple things. First of all, once the car is car is warmed up, even if the HVAC blower is not operational some heat does flow through the vents due to ram air pressure, but trust me -- it's not much at all. Second, I found I could take advantage of the unit's non-volatile memory that stores the last temperature and fan speed settings. I adjusted the temperature on both sides to 80 degrees and set the fan speed to about 3/4 of maximum so that when the controller was operating it would generate enough heat to warm the interior sufficiently to compensate for the periods in which it did not work. This had the unfortunate effect of blowing lots of cold air shortly after start up but that was a small price to pay for warmth throughout the drive.

While this little "trick" made the car drivable, by the drive home Tuesday I had had enough.The weather forecast was for cold but sunny weather the remainder of the week so I decided to bring the E46 out of its lair. I hadn't driven the car much since the rear suspension overhaul so knew this would be good for the car as well as good for me. Of course, nothing is ever easy. While browsing my favorite weather site during lunch on Thursday I realized to my horror that the forecast had changed and some light but accumulating snow was predicted for later that afternoon...just in time for the commute home.

As I learned many years ago when I foolishly tried to run summer (not all-season) tires on the E36 in winter, a half in inch of snow might as well be four feet: summer tires make the car downright dangerous to drive in those conditions. I wasn't about to lose my pride and joy just to keep my employer happy so I ditched work a couple hours early to grab the E36. It didn't take much to rationalize the move: better cold than spun out in a ditch, right? And good thing too...I had just managed to put the E46 to bed and close the garage door when I saw the first snowflakes appear.

By the time I got back to my neighborhood 15 minutes later we had about 3/4" of snow on the ground and the ABS was getting a workout. I had to stop at the food store on the way so I took the opportunity to grin a bit, turn off ASC, watch out for the Federales (and, for that matter, the light poles), and play around with the effects of reduced friction in the largely empty parking lot. Mercifully, the HVAC controller decided to play nice and I had heat nearly the entire trip home. What can I say? The car doesn't always love me, but I think it respects me...and I can live with that.

Fast forward to today. The parts came in, I pulled the climate control unit, drove home with it in the E46 and proceeded to swap the defective capacitor with a new tantalum part. I ran into a small snag when I realized I'd forgotten my micro screwdriver set back at the garage, but since I knew full well it didn't have the micro (T7) torx driver best suited for this job I just ran over to Eppy's and picked up a nice 41 piece precision bit set by Sunex Tools for a mere $28. While there, incidentally, I learned that Ideal tools bought SK Tools out of bankruptcy. The CEO of the company told Eppy's management that they expect to be shipping again in March and that they were planning to keep the manufacturing facilities in the US. Hearing that I confirmed my commitment to SK Tools, and good thing too....I have a lot of them.

Back at the workbench I took the opportunity to do a little preventative maintenance and replaced the HVAC temperature sensor fan. While not exactly cheap at $125 I felt it was best to do it while I had the unit out of the car. Interestingly, I discovered that the fan lacks a tachometer output, so I know the HVAC controller hardware or firmware is not monitoring the fan's speed. This in combination with its near silent operation would make it damn near impossible to detect a failure. And since stationary DC fans present a load equivalent to a short, I felt it better to replace the fan now rather than risk possible future damage to the controller I was working so hard to preserve.

On the way back over to the garage with the newly repaired controller I found myself a bit on edge because I could not bench test the unit and so I could not be 100% sure the repair was completed successfully until I reinstalled it in the vehicle. Once I arrived at the garage it took me less than two minutes to pop the OBC and HVAC controller back into the stack, reconnect the battery, and turn the key -- to find the controller working as expected. The acid test, of course, was the 20 minute drive home from the garage...the controller never skipped a beat. My feet were nice and toasty, and I took time to bask in the warmth of the knowledge that I'd just managed to save myself $470 in parts and $130 in labor, or $600 total in little more than two hours of work. I'll say it just in case it isn't obvious: that is one hell of a DIY dividend.

Naturally, I took a bunch of pictures of the process and observed at least one thing that wasn't covered in the DIY I followed. Therefore I hope to publish a DIY of my own as soon as possible.

Mileage: 201320, Tools: $28, Parts: $125, Parts Saved: $440, Labor Saved: $130