Well, there has been alot of discussion about belt chirping onthe LS1s. Most of the time the reason has been categorized as one of two sources:

1. Worn belts
2. Worn pulley bearings

Well, I found a third reason, at least for the AC belt system. The story: I had the crank pulley replaced along with the water pump and various other items to include a new AC belt. After the work had been completed over the next couple days I noticed chirping/squealing coming from the front of the engine. I squirted water onto the belts in an attempt to isolate the problem (belt versus pulley bearing). Water on the belt, noise went away. Cool, belt. Somewhat odd in that AC belt was new, but, ok. Put another new belt on, noise still there. Hmmmm. Pulled idler and tension pulleys to examine. No visible issues with the bearings, however, the pulley surface that the belt rides on was very worn (actual ridges/grooves) in the surfaces that are supposed to be smooth. Replaced both pulleys with after market (metal) pulleys and problem solved.

It appears the stock pulley are made of a plastic/composite material rather than metal as the after market pulley are.

Again, this was a new source for belt noise, at least for me, and can not be readily differenated from a bad belt using the water test method.

Hope this is helpful to others.

Regards,

Danny

 

Yes, the worn surface can cause noises too. Glad to hear you got it stopped fairly easily.

FYI, I put the cheaper metal pulleys on for the AC and one hardly lasted 5k miles and I had to replace it again so I went with the more expensive composite one.

 

What failed, bearings or surface?

Danny

 

Bearing. It was chirping again.