Evil Gnome

Background: My 98 TA underwent an LQ4 swap due to engine issues. In the process, the belt snapped and broke the plastic power steering pulley and bent the alternator pulley. The power steering pulley was replaced by a metal one and the alternator pulley was replaced by the pulley from the alt in the Sierra I got my engine from. As anyone whose done this swap will know, the alt bracket needed to be drilled into the block. I say all this because these are the only things I can think of causing my issue.

Issue: Approx 3000 miles later I started getting an awful belt squeal. I have replaced the tensioner and every pulley except the alternator and power steering (and the belt after every change). I've been told by several mechanics never to come back because they can't figure it out and it's cost them too much.

Does anyone have any suggestions on which pulley to start with? I can't seem to find just an alternator pulley so that would mean a whole new alternator. I don't want to keep throwing money to fix what ain't broke you know?

I'd appreciate any suggestions.

sams02Z28

Are you positive that its your belt? Check your water pump,sounds almost the same,an if it is your belt,maybe try some belt conditioner!!

RezinTexas

Even one drop of oil on a belt can cause bad squeaks. spray down all the pulleys with brake cleaner and put on a new belt.

If that is not the cause, try pressing on the PS pulley on 100%, then back it off 1mm.

99VetteFRC

Next time the belt is squeeling, put a wrench on the tensioner and take the tension off the belt while running and see if it goes away, then tighten and see if it gets worse. That may help with a diagnosis.

camcamaro1991

iTrader: (18)

I ran into this issue a while back when I purchased a AD244 alt...
I found that the alt... pulley was pushing the belt forward (towards the front of the vehicle) by a few millimeters. (I pulled both pulleys my stock alt and the new AD244 pulley and set them down and measured them, it confirmed my findings) I swapped the alt pulley back to my F-Body pulley and it resolved the issue. You also need to make sure your power steering pulley is also aligned correctly, since you can actually adjust it in and out on the pump shaft.

It sounded like a timed “squeaking sound” almost like every time the belt made a rotation in a certain spot it would squeak , that was based on RPM, the more RPM the more it squeaked.

Evil Gnome

Thanks for the responses.

Cam, that sounds like the exact issue I am having. I can confirm the sound originates on the idler pulley between the power steering and alternator. Do you know where one could find just an alternator pulley? I can't seem to find one without buying a new alt.

Vette, I will test that. I just replaced the tensioner as well. Whenever I get a new belt, the sound goes away. After driving it for a bit is slowly comes back to a loud squeal. That's why I know it's a belt issue to answer sams.

Rezin, I thought this might be the issue as well. I can confirm spraying with brake cleaner makes the chirp go away for about a second or two. My only issue is I can locate the sound to a specific pulley as stated in my answer to Cam.

camcamaro1991

iTrader: (18)

Unfortunately no I do not know where to get just a pulley, maybe from a GM dealer, or find a used alt from either your local junk yards, eBay or craigslist.

I forgot to add, the first 2 times I replaced the main belt with a new one the sound went away for about week or two, but squeak always returned. Even after trying to align the power steering pump pulley a few millimeters each way forward & backwards on the pump shaft.

good luck