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Squealing Noise- Idler Pulley or ?

38K views 11 replies 9 participants last post by  Chickenhawk 
#1 ·
Okay, so I started up my TB for the first time in a while Saturday (but it's being regularly used by someone else), and there was this terrible squealing noise. Rather loud, definitely heard it inside the car. So, I popped the hood, and tried to figure out what it was. I'm pretty sure it was coming from the left side of the engine (as I'm facing the front of the truck). Is this the idler pulley? I think it was the larger pulley on the top, not the smaller one on the bottom, but I didn't stick my head down there to find out. :D The noise also went away slowly, kind of degrading into an occasional sqeak (every second or two), and then it went away. Maybe the belt's slipping around the pulley? I'm not sure. I looked up idler pulley, but most of the posts seemed to be about a whinning noise, which this is definitely Not. Well, I do have an occasional faint whinning noise, but I think that's the power steering pump (it's barely noticeable). What do ya'll think?
 
#2 ·
I have 122,600 miles on mine.
It squeeks under certain conditions...
after 'heavy' rains.. the next morning it squeeks and slowly goes away...
and this morning- it got cool/humid overnight after a few days of 95-100 degrees... it too went away within 4 blocks of it squeeking...
to test if its the belt- you can use a spray bottle and spray the belts underside to see if it goes away...
(My belt has about 15K on it).
 
#3 ·
you can use a spray bottle and spray the belts underside to see if it goes away...
(My belt has about 15K on it).
What he said!
I just use a cup of water and trickle a little onto the belt (while it's running) - if it's the belt it will stop almost right away, but only temporarily.
 
#4 ·
Mine does that sometimes. Always has to one degree or another. Meaning to ask the at the dealership one of these days when I bring it for service.

Seems to me there was something I read in the manual about a noise which is normal when it's cold and goes away as you drive. Maybe not the same noise but maybe something associated. If I find anything out will post it.
 
#6 ·
Mine normally does it when it's cold/damp too, but the thing is that this was pretty much the quintessential mid-spring day- Upper 70's temps, sun shinning, etc. And it had been started the day before. And it wasn't just making a faint noise. It was Howling. Very embarrasing if you had to drive near anyone. I'll definitely have to give the water on the belt thing a try, maybe that'll solve it. If it does, does that just mean that it needs a new belt?
 
#7 ·
It may not be OLD and ready to fail- but something may have gotten on it and now it squeels....
At about $30, its an easy fix.
Make sure you get water in the belt only....
dont want to overspray a moving part that may get quiet dues to the overspray and then you replace the belt only to find the squeel is still there...
heres how to remove the belt... release the tension on the belt by turning the tensioner... the belt then practically slips off...
follow the routing using the diagram on the fan shroud (see my pic)
im using a ratchet and a breaker bar

 
#8 ·
FYI, If you have the factory belt....
try to get the AC-Delco #'s off the belt... you may have to crank engine to turn the belt.
A good parts guy can cross reference the belt # to an aftermarket belt.....
the other option is to KNOW which alternator you have....
theres 2 options out there- last I heard... I think the higher AMP one uses a different belt (I think its the alternators pulley or something)....
I was asked this when I went to get mine- I didnt know- and the guy was knowledgeable enough to cross reference the part from the belt....
 
#9 ·
:iagree:

There are 2 different belts. If you get the longer one and your vehicle calls for the short one, you will have an issue w/ the belt slipping, especially when cold.
 
#10 ·
I had the same issue after buying an aftermarket serp belt. Called dealer and gave vin. This is the dealer part I was given:

GM#12575215

It was slightly shorter than aftermarket, and after install, no more squeek/squeeling.

This site is great, already saved a few bucks.

Thanks all.
 
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