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.
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