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Monday, July 22, 2024

Doug's Domain

Doug Vetter, ATP/CFI

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Saturday, May 28, 2011

Mechanical Tensioner Noise

Back in 2007 I noticed a rattling noise with the engine at idle. At the time my technician helped me trace it to the vicinity of the main accessory belt tensioner pulley so I replaced it. Unfortunately, while that was certainly part of the problem, it didn't completely eliminate the noise so I wound up replacing the tensioner as well.

Over the last couple of weeks I noticed that the noise had returned and as usual it was most prevalent at idle and when the engine was cold (i.e. first thing in the morning). So I figured I'd cut to the chase and order a new tensioner / pulley kit and install it this weekend in concert with other work I had planned. Imagine my surprise, however, when I looked up the part number and saw the dreaded word "ENDED" associated with it. I then read the fine print and found a ray of hope -- it was superceded with a new part number. My hopes were quickly dashed, however, when I traced the new number to a hydraulic tensioner conversion kit.

For those that don't know, these engines came from the factory with either a mechanical or hydraulic main belt tensioner. The mechanical variety is the "economy" option and is typically found on non-M vehicles. They tend to fail on a regular basis (72K is an ideal preventative maintenance interval) but at roughly $70 including pulley, replacement is seldom a financial concern. I learned long ago from my technician that the hydraulic tensioner is the high quality option and they tend to last "forever". My personal experience with the hydraulic tensioner governing my A/C belt would seem to bear that out -- while I've replaced the pulley a couple times the tensioner is original with 208K miles in service. But quality costs money, and this is no exception.

This explains, of course, why I didn't convert to the hydraulic tensioner back in 2007, and as I found out during a recent visit to my friendly neighborhood BMW parts counter, little as changed in this respect. The kit (sans pulley and other assorted hardware necessary for the conversion) is now $210. While some may think I like spending money on my cars, nothing could be further from the truth. Assuming I have a choice in the matter, I'd just as soon spend $70 vs. $200, but if I want an OE solution and a quality one at that, I'll have to splurge. And it's probably just as well if I never have to hear that annoying rattle again.

On the same visit to the dealer, I cornered my technician long enough to ask him about the conversion process. He said he just had to do this on his own E46 and was kind enough to print out the service information (SI B 11 04 03) governing the conversion on the E46 and later vehicles. The E36's M52 application wasn't specifically mentioned, but the SI gave me the information I needed to order the necessary parts. I'll provide the full parts list as well as the procedure to replace it in a future blog entry.

1M In Person

I finally got to see a Valencia Orange (VO) 1M in person at the dealership on Friday. Sorry, no pictures, as I didn't have my camera, but this is what I'm talking about. This particular vehicle still had all of the usual door protection moldings on it so I knew it was fresh off the carrier.

While I didn't dare sit in it out of respect for its new owner, peering in its open window I realized that BMW managed to keep the basic design of the 135i interior intact which, while not ideal, is a huge improvement over the nightmare designed for the E9x vehicles. The downsides of the 1M interior in my not-so-humble opinion include its use of alcantara as accent material and the colored stitching. I'm not a fan of alcantara because, like all suede fabrics, it wears poorly. It also offends my OCD in that its texture produces something of an "archaeological record" of its encounters with humans. As for the colored stitching, I think it looks great on the VO car, but only because it matches the exterior color. On a white or black car orange stitching will look out of place...even tacky. In the immortal words of Yoda, "do or do not...there is no try". Either give us white stitching on the white cars and gray or black stitching on the black cars, or don't bother.

(Image: Blackstone Labs oil analysis report on 6/8/2011 at 208800 miles) I found the body kit in general a bit too aggressive for my taste (I prefer conservative, or "sleeper" styling), but taken as a whole with the widebody, the exterior design simply works. It's -- dare I say it -- refreshingly retro and more in line with BMW's roots. And I thought I'd dismiss the exterior color as too flashy, but in person I found VO dances beautifully with the sun and highlights the aggressive exterior design. Still, if I had my choice (i.e. I could actually get an allocation and pick my color) I'd likely go with white. I've never been a fan of white on vehicles, but the pessimist in me is all too familiar with the fact that black is a nightmare to keep clean and white will be easier to blend than VO when (not if) something bad happens. Next time, BMW, I command thee to offer Estoril Blue, or any blue for that matter. You limited the color choices on a limited production vehicle. I get it. Would it have killed you to offer one more color?

A good look under the vehicle revealed its M parentage, and its underpinnings are probably the most attractive aspect of the car to me. My technician confirmed that the car borrows essentially the entire M3 suspension with the exception of the front subframe, which is great from a perspective of future parts availability. Interestingly, he also mentioned that the car is actually slightly wider than the M3, presumably referring to the fender flares.

In spite of its unfortunate reliance on complex and failure-prone turbocharging and direct fuel injection systems it should come as no surprise when I say that the 1M is the only car to come out of BMW's design group in the last ten years that I would seriously consider buying. In fact, as I walked around the 1M with the E36 parked a scant 20 feet away, I selfishly wondered whether it was time to move on, put the E46 into daily service and buy a 1M to take its rightful place in the garage.

Anyone want to make this easy for me and offer to buy the E36? :)

Oil Service

They say that when you start to go crazy the first thing you lose is your sense of time. If that's true, I'm the sanest man on the planet as I realized, without so much as a glance at my maintenance schedule, that it might be time for an oil change. A quick check of my records confirmed that around 4600 miles had passed since my last oil service so I picked up an oil service kit and completed the task in less than 20 minutes.

I decided to take an oil sample this time after skipping it last time. This will give me additional trend data to confirm the engine remains in good health after its recent lead wear scare.

Six quarts plus an oil filter came to $45. An oil service is now $200 at the dealer, so that is reflected in my Labor Saved column.

6/8/2011 Update: I received the oil analysis today. All in all it's a good report but, as you can see, lead appears to have increased slightly for this sample and this is the first time fuel dilution has been mentioned. I think the lead value is still in the "statistical noise" but it may very well be the result of bearing wear typical of an engine this age and thus the "new normal". I suspect the fuel dilution is the result of ring wear but, as indicated in the report, anything below 1% is normal so I'm picking nits here. In spite of these changes, I'm still planning to skip the sample next time. Cost for the analysis is now $25 so I've noted that in the Labor column.

Mileage: 208800, Parts: $45, Labor: $25, Labor Saved: $150