Help!!! Timing belt rubbing???

[bimmerboy12]

Hi all I could really use your help... put a new timing belt in my 88 325iC and along with it t-belt tensioner, belts, hoses, camshaft seal, cap, rotor, wires, oil pan gasket etc. Well got it all back together and I get a horrible RUBBING sound... a rythmic sound like the T-belt going around and rubbing something. I took all the other belts off and it still does it. I assembled everything properly so i thought and then I thought, what makes that belt centered on the toothed pulleys? The old belt I took off ran on a tensioner pulley that had a split in the middle of it, like a depression, and the belt had a raised portion in the middle of it that it ran in... this must have kept it centered, or it created it I don't know. Anyways, what keeps it centered since it is a flat belt? What could I have done that is making the belt wander? I tensioned it with the spring thingy that pushes off the water pump. Any help would be huge as I am DEAD IN THE WATER with this damn thing after dumping an entire two days into it.
Thanks!
Brian

[bimmerboy12]

update: so I tore it all back down. Looks like the outer edge of the timing belt is rubbing on the crankshaft pulley mount. what the freakin hell. I thought these were supposed to self center to prevent this???????

[bimmerboy12]

No ideas??? The belt is rubbing hard on that crank pulley mount, which means it wants to migrate outwards away from the block. I tried shoving a .010" feeler gauge in between the belt and the pully mount and could not even force it in there. I called bavauto and they said it sounds like something to do with my installation- thats it.
WTF???

[87-325ic]

if the old one didnt do it, and this one does, maybe it is due to your installation.

when you installed the belt, had both ends lined up and the tensioner putting its tension on, Did you rotate it a few times to double check the timing? you should do this, and while doing it, look at how, why, and what is causing the problem.

sounds almost like the two pulleys are not quite square with each other though.


good luck.

[Hallen]

I had a situation with my old timing belt where the belt was rubbing against the timing belt cover housing. I suspected it was due to an old tensioner and not enough tension.

I replaced the belt and the tensioner. I just took it all apart again, and there is no more rubbing and the belt was squarely positioned on the sprockets.

[handysmurf59]

I had the same problem on my iC when I went to change the belt last time. About a 1/4 in of the belt was missing. Ouch! It was rubbing against the timing cover stud. Purchesed a kit (Conti if I remember right) from Pelican and I've got about 1k of hard driving on it and all is good. Never had any idea of what caused it, but replacing every thing seemed to fix the problem.

[rodrigo]

I did this last summer to my car, but vagely remember in very specific detail. I remember taking off the cam-shaft pulley to replace the seal and the cranksghaft pulley and toothed balancing weight to do the lower seal.

Are you sure you placed those back the proper way? Its the only thing I can think of.

[bimmerboy12]

PROBLEM SOLVED: It was a faulty tensioner. I took off the timing belt and the tensioner pulley had about .020 thick of rubber in a wavering pattern on it from 15 seconds of the car running. Its axis was obviously not perfect. You could spin it and the rubber on it would run back and forth. It was throwing the belt back and forth causing the noise. One of those random things I guess.
Got a new belt and tensioner and installed... all is well... except now i have a stumbling issue when the car warms up. I love my E30.