Timing belt noise

[Project560]

Good afternoon! I think that the timing belt on my 84 NA is rubbing on the plastic behind the belt. I noticed it a month or so after I changed the belt last year. It is more noticeable when cold and seems to be coming from the crank pulley region. Is it just a matter of loosening the belt and sliding it forward or is something else going on? I changed all of the idlers and tensioners when I did the belts. Thanks. I have a video but I don't think I can post it here.

[OK-944]

I am suddenly forgetting the correct orientation of the crank pully - but I know that its important not to put this on backwards.

Another check would be to look carefully...perhaps with a bright light shining at an indirect angle to the rear timing cover - to see if there are small bits (almost like black dust) being cast off of the belt, and also by checking the actual belt along its edges.

Finally...you'd mentioned that the belt was changed recently - and that you hear this noise when the engine is cold. Question: have you yet rechecked (and possibly re-tensioned) this belt? This should be done at around 1K miles after a timing belt change, as this belt can tend to stretch a bit early on, and a belt which is a bit loose would have more tendency to be a bit "floppy," (and more prone to make contact with the timing cover) especially before the engine has a chance to warm up which will, in turn, tend tighten the belt a bit.

[pfarah]

Hi there. If the belt is rubbing, you've got something not correctly aligned. Please make sure that your crank TB pulley is not on backwards and the metal spacer is there. Things are pretty tight in there but it all goes together just so and any rubbing is not Kosher.

[Project560]

Thanks. I will have a closer look. I haven't re-tensioned them because I didn't put many miles on the car before winter, but I will check.

[Project560]

Thanks Patrick. I didn't remove the crank pulley when I did the belts, but that's not to say that something isn't messed up. I don't think it made that noise before I did the belts, but I didn't really run it much because it had been sitting a long time before I bought it. I will have a closer look and see if I can see anything. The crank pulley does seem a bit out of round (or at least the one for the power steering belt). If you want to see a video I have one posted on Facebook on the Porsche 944 No Spam group.

[pfarah]

If you suspect something is out of round, you may also want to use a dial indicator to measure crankshaft play. Sorry, I actually don't have a Facebook account.

[Nigel Haslock]

Note that the power steering pulley is not self centering. You need to check that it is centered before torquing down the crankshaft bolt. I checked the gap between it and the alternator pulley with a suitably sized drill bit.

[Project560]

Thanks guys, I will check these things.