Bearing squeal Cold weather

[Michael Calverley]

So here's a weird one. My 2004 GMC Yukon 4.8 has what sounds like an accessory bearing squeal on start up but only in sub zero temperatures. Squeal goes away in 30 seconds to 3 minutes depending on how cold it is. The colder it is outside, the longer it continues. It's coming from the front of the engine probably from the serpentine area. My mechanic is having a hard time sorting it out and has changed the idler belt tensioner bearing assembly  out so far which didn't solve the problem

Any thoughts or experience with this?

[davester]

So, taking the belts off and spinning each pulley by hand doesn't give a hint where the problem is?

[tlaw91]

Your truck wants you to remove the ac belt and tensioner, throw it in the trash, and install a 2010+ GM stretch belt.


Sent from my iPhone using Tapatalk

[William Christopher Speight]

Had the exact same issue changed, serpentine belt, idler pulley, and ac belt all at once and it went away.  Also changed my starter too.