2004 tahoe whining not serpentine belt tensioner or idler pulley

[Vincent Mitchell]

I just replaced the tensioner, idle pulley and serpentine belt and the squeal persists. high pitched whine like power steering belts of old but no wear present on the replaced belt. What should I check next?

 

[Doubeleive]

I just replaced the tensioner, idle pulley and serpentine belt and the squeal persists. high pitched whine like power steering belts of old but no wear present on the replaced belt. What should I check next?

Did you check and or change the ac belt or tensioner?
it's pretty typical for the ac tensioner to be noisy, particularly on a cold start int he morning.
a easy way to check would be to simply pull the belt off and let it dangle, just stick a ratchet drive in the center hole of the tensioner pulley and twist to release tension.

 

[Vincent Mitchell]

Good to know. I'll try and let you know. Are new ones any quieter?

 

[Miami-Dade]

I just replaced the tensioner, idle pulley and serpentine belt and the squeal persists. high pitched whine like power steering belts of old but no wear present on the replaced belt. What should I check next?

Moved you here from the 2024 section.

 

[Doubeleive]

Good to know. I'll try and let you know. Are new ones any quieter?

it can be hit n miss

 

[strutaeng]

Yeah, just remove both belts to rule out accessories.

Also, try to make a DIY megaphone from a cut plastic jug and a long screwdriver. South Main Auto showed how to make one and seems rather effective in finding these noises that are hard to pinpoint. I'll see if I can find the video.

Edit:

 

[OR VietVet]

Get a mechanic's stethoscope and keep it handy in the tool box.

 

[Vincent Mitchell]

I replaced both tensioners and idler pully and belts. There is atill a high pitched whine that goes away if I rev it a little but comes back at idle. At this point I think I need to localize the sound. The components on upper belt are Water pump, Alternator, Power steering pump. Lower belt is AC. At least I think that's what it looks like.

@strutaeng,

I wasn't sure If i could just try removing the belt to isolate which one has the noisy bearing. Is that safe?

 

[Vincent Mitchell]

Moved you here from the 2024 section.

Thanks. I misread the section.

 

[strutaeng]

I replaced both tensioners and idler pully and belts. There is atill a high pitched whine that goes away if I rev it a little but comes back at idle. At this point I think I need to localize the sound. The components on upper belt are Water pump, Alternator, Power steering pump. Lower belt is AC. At least I think that's what it looks like.

@strutaeng,

I wasn't sure If i could just try removing the belt to isolate which one has the noisy bearing. Is that safe?

Sure. Just idle it briefly and keep an eye on temperature because your fan, water pump, etc. obviously won't be working. May be better with a helper on the cab watching while you are listening in the engine bay.