Trying to narrow down a belt squeal

[Mike Daley]

on my 2012 5.7 i have an annoying belt squeal. When it's cold it's all the time, when it warms up it's only over like 800rpms roughly. Sprayed the belt very lightly with wd-40 and it stopped instantly. So I figured it was the belt. Removed the belt and it seems in perfect shape. Not dry and cracked or tearing. Upon further investigation I found a bad idler (replaced this about 6months ago) and a bad tensioner pulley. Replaces those and the belt still squaled. Removed the belt again and noticed that the power steering pump shaft will walk out maybe about a 1/4" or so if I had to guess. There is no play up or down, only in and out. Is this normal or is this the cause of the noise?

 

[Torrch]

I'm having the exact same issue on my 2012 5.7 I just bought used from the dealer. I took it back to them the day after I bought it and they replaced the belt. no more than 4 or 5 days later it started squealing again. Did you ever figure it out?

 

[JohnnyMac]

If any of your pulleys are not in exact alignment with the rest, the belt will squeal. There is a good youtube video that shows how to diagnose and pretty much pinpoint your belt noise so you might do a search there.

 

[sbarron]

also check that the belt isn't glazed, (shiny), from prior slipping. could look perfect otherwise, but still slip.