Hey guys, I just did my head gasket recently, but am having some trouble with my timing belt. Its making a whining noise. I asked a BMW mechanic I know and he said it was probably just a little too tight, but the sound should go away in afew weeks. I let it go for afew weeks, but it seems to be louder now! I replaced the tensioner with the belt, maybe its defective? I decided to try and relieve some of the tension while not loosening the belt completely because Ive heard that if this occurs, the belt will relax and have to be replaced. I think this may be the case now though, because when I relieved it enough to stop the whining, the belt had a visible vibation of about a 1/4 inch either way when I hit the throttle. I tightened back up, but it still vibrates. Should I replace it again? or is it safe to drive with aslong as I take it easy?

As well, I noticed the engine has a miss that is especially noticeable at idle. I changed the cap, rotor, and plugs, but didnt do the wires (likely original). Is this a likely explanation?

Theres also a clanking sound coming from the rear when I hit bumps, oh yes its an 89' 525i by the way.. Could this be trailing arm bushings or sway bar? Ive checked the exhaust and it looks fine.

Any help would be great! Thanks.

If it's actually the timing belt making the noise, the tensioner bearing is probably the culprit. You should be able to tighten that timing belt as much as possible and not have it make noise. Also the waterpump bearings may be failing. Did you replace the waterpump with the timing belt?

The engine miss could be any number of things. BMW pulg wires last a long time, but after 18 years, it may be time for a new set - they aren't cheap.

The clunking in the rear is likely a shock mount (easy fix) or the rear subframe bushings (more difficult).

Good luck!

If it's actually the timing belt making the noise, the tensioner bearing is probably the culprit. You should be able to tighten that timing belt as much as possible and not have it make noise. Also the waterpump bearings may be failing. Did you replace the waterpump with the timing belt?

The engine miss could be any number of things. BMW pulg wires last a long time, but after 18 years, it may be time for a new set - they aren't cheap.

The clunking in the rear is likely a shock mount (easy fix) or the rear subframe bushings (more difficult).

Good luck!

Yes, I replaced the water pump too. Do you think the timing belt is still ok though? should I perhaps get a new belt and put the old tensioner back in place, since it seemed to be fine? Thanks.

Are you certain that the whine is from the timing belt and not from some other rotating part (alternator, PS pump, A/C compresssor, wather pump)? A bit of work with an automotive stethoscope should reveal the source of the noise. If it is originating from the timing belt I'd replace the belt and tensioner with a new kit. Either a Conti or OE parts from your dealer.