Been having problems with belt squeal for a while now and now sure of the cause. The belt has maybe 750 miles on it. I rechecked the alignment of the pulleys and that all checks out. Idler pulleys roll smoothly. Alternator rolls smooth. Powersteering pump turns smooth. The squeal in the attached video is very minor to how bad it can be. Sometime is will squeal right on startup and get worse as the rpms climb. Goes away when it wants to and comes back when it wants too. Will also note that even tho the power steering pumps turns smooth last spring i did have a hose fail and lost my fluid while i was driving and had to finish my 30 minute trip without PS. After fixing the hose all seemed fine. I plan on trying a new belt tomorrow but wanted to make this post anyways incase there is something im missing. Also if i remove the belt there is no squeal.

 

I suspect that the p/s fluid has "lubricated" the belt and caused the slip. Either that or the belt tensioner is weak or broken.

 

Clean the pulleys and tensioner surface before installing the new belt.

 

Oh, sure Fred, go for the easiest and best solution!.... ;-)

 

OK.... so I'm Captain Obvious ......

 

The belt "tensioner" is likely tired....should be replaced when replacing the serpentine belt

 

Well it turned out to just be the belt. The belt i replaced only had maybe 750 miles on it and appeared clean.

 

I've never had much luck getting (all of the) oil or antifreeze off of a "dirty" belt.