Could be the timing belt tensioner pulley or any of the others, I would
remove the belts and spin the accys. over by hand to see which is making noise.. could be water pump, A/C pulley bearing, power steering pump, alt..You won't know until you take the belts off and spin them.. Or if you have a good ear you can use a mechanics stethoscope or a long piece of tubing or a long screwdrive that you can put up against the suspected items an put your ear against the other end and listen for the noise while its running but extreme caution must be used while doing this for obvious reasons.
Quote:
Originally Posted by Shimamura3
1990 525i (M20) 5spd w/184,000 miles.
I plan on doing a full (Bentley in hand) Service II including replacement of the timing belt/water pump and all other belts & fluids and O2 for the first time. In addition to asking for advice for a first timer I'd like to ask if anyone knows what pully bearings up front are prone to going bad. My car has a pulley noise up front that I can't locate for sure. It's not a belt slipping or a vacuum leak, but that constant whine you usually hear coming from a Ford POS. I'd really like to fix the wheezing sound while I have everything torn down up front.
Also, what is the best oil for the manual trans?
Thanks for your help!