Thread: Accessory Belt Slip

OK, I was hearing was chattering from my accessory belt tensioner, but the belt was still fairly tight. I was starting to hear a sqealing sound when the engine was cold and sometimes when I would turn after it was warmed up. I changed the belt and this made no change. I then changed the noisy tensioner. The chattering is now gone, but the belt slips. The belt slips bad enough that I can read the size of the belt while the engine is on. SO, I hit it with some degreaser and warm water. I figured the coolant left a film on the pulley. I did this and the belt was moving the way it should. A few hours later I started the car and nothing but squealing. I decided to take out an old spray can of belt dressing and hit each pulley. It seemed to help when I hit the crank. I double checked that the belt was positioned correctly and then hit the pulleys with degreaser again and rinsed with warm water like last time. Everything was good again. Get up this morning, ran good for 15-20 seconds and then started to squeal.

So I read a few things about running chaulk on the belt while it is running to clean the belt. I am going to try that. If that does not work, I am going to check to see if the pulleys spin freely, clean each pulley with brake cleaner and wash the belts with soap and water. Any one else have anyother suggestions?

Mods that matter
electric water pump, gates k060874 alternator overdrive and triple checked the belt position.

oops, forgot to add that I replaced the belt last weekend with the same size

2003 GTP stock belt size is 91.5 and I am running 87.4 with the electric water pump.

The crank pulley is about the least likely thing to cause slip, due to the amount of wrap, and being on the ribbed face.

Are you running an oversized pulley on the tensioner? It seems that if you leave the 3.0" stock one, the belt can run into itself when passing back down past the P/S pump.

Here's a pic I took trying a 4.0" pulley I found at a yard just to mess with (3.5" is what many Meziere folks run):


You can see how close it is, even though it's not snugged up. Also remember, it's a full inch bigger than the stock pulley, which brings the P/S side and W/P side closer to each other on a 3.0". Going larger also helps tighten the belt & bring the tensioner pulley down to a better position that moves the belt further away from the P/S pump, too.

Couple that with the fact that this is the driven side of the crank pulley... meaning the crank is "pushing" the belt outward as it comes up that side, which will bring it closer to the P/S pulley as well.

- Dave

The Meziere head isn't as big as the pulley, I was just mocking this up a few months ago with that big pulley in different arrangements.

As far as the belt, it being possibly too long is only about 1/4 of the reasoning I used above. If that was my only point, my reply would've been alot shorter.

- Dave

Good luck to you, sir. Just remember that it's a reverse-threaded (left-handed) bolt on the alt. tensioner.

- Dave