Two years ago, the then nearly five year-old belts on my E36 would be pretty noisy on cold mornings, for a few minutes. The belts still looked pretty good, but I replaced them with new ones 1½ years ago. Last winter, no noise on cold mornings, but this year, the noise is back. These belts are only 18 months old and have probably only about 15K miles on them. These things shouldn't be whining already should they? They still look practically brand new.
-- Graham
If you used belts from the local car parts store then you will have these problems. I have heard that the belt cross section on European belts are a bit different from ours and the difference causes these problems.
I am basing this on what I hear often on the Audiworld forms.
They recommend buying from your friendly audi stealer.
T> Two years ago, the then nearly five year-old belts on my E36
I recommend you readjust the belt tension. They stretch reguardless of who made them or what engine they're on.
Isn't this automatic? It is on my older E39.
This might due to:
An idler pulley or a water pump bearing's grease drying up. I've found the same problem on many cars, and localized it to the idler pulley in most cases but, the water pump in some cases.
The new belt just ran the bearing at a higher pre-load and got the grease moving a bit.
I hope this helps?
Refinish King
The car has belt tensioners.
-- Graham
There is no belt tension "adjustment" on BMW E36 engines. There are automatic belt tensioners for both the Alternator-Waterpump-Power steering belt and also the AC belt.
I have seen one where the mechanical tensioner developed a "set" (a detent) from engine vibration while sitting in the same place all the time.
This made it hang up so that it would not apply the correct tension once it reached the detent. Replacing the belt would temporarily alieve the problem until the new belt stretched to the same length as the old one and the tensioner reached the detent.
I'm betting that this is what is wrong with yours. To check it you can remove the belt and exercise the tensioner throughout its full range of motion. It should be smooth, with no detents, hangs or bumps. If not fully smooth, replace it (they aren't that expensive) and you should be able to put back the current belt. It should be fine.
Belts should not make any noise even as they become worn. They should just get to the point where they noiselessly fall apart. That's why we replace them prophylactically. Belt squeel would indicate either a tensioning problem or possibly that one of the driven devices is binding.
-Fred W
Check your alternator mounting bushings. They've probably deteriorated by now. You'll keep chasing loose belts until you replace them.
If you do it yourself, the polyurethane replacements are far easier to press in, and work just as well as the rubber.
Matt O.
The belt tensioners have bearings in them:
I'd advise to take the belt off at night, then spin the tensioners, water pump, A/C pulley and water pump in the morning when it's cold. That will isolate the noisy component.
I hope this helps?
Refinish King
How do these automatic belt tensioners know how much tension to apply? Is there a spring? If so, isn't it possible for it to fatigue?
Thanks in advance.
-Ted
Yes, spring tension. There are two types. One that has a little mini-shock absorber looking spring assembly and one that has a torsion type spring assembly. You'd have to look up your car to see whaich you have. And yes, either way it is possible for them to go bad.
-Fred W
Dunno about BMW. FWIW, on the Alfa 2000 GTV I had back in the 70s, there was an oil pressure operated chain tensioner. I think there was also some kind of ratchet arrangement to keep the tension, once it had been adjusted.
We were talking about the drive belt tensioners, not the timing belts/chain tensioners.
-Fred W
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