Eliminating squealing from under hood 2010 Silverado 1500

[Snagglefoot]

My son’s Chevy Silverado has a lot of squealing going on under the hood. It has 190,000 miles and pretty much all original components. It’s pretty hard to identify all the sources, even with a mechanics stethoscope. We’ll start with the tensioner and idler pulleys. We do the work when he visits so this might take a while. This next session we’ll do the two pulleys and check out the alternator, power steering pump and harmonic balancer. I can see a wobble on the harmonic balancer so we might have to replace it. Stay tuned. This might take a while. Suggestions and ideas are well appreciated.

Here are the initial parts from Rock Auto:

 

[AZjeff]

Did he buy it with the high miles and squeals?

 

[dfarr67]

Talk about shooting the parts canon.

 

[Snagglefoot]

Talk about shooting the parts canon.

I disagree. I’ve done a few high mileage GM’s. Gernerally you get those two pulleys changed, then check out the other components. Those photos represented just two pulleys with front and back shots and the boxes they came in. YRMV.

 

[Snagglefoot]

Did he buy it with the high miles and squeals?

He’s had it for several years and the squeaks slowly developed. Time to take care of them.

 

[CapitalTruck]

That pulley/tensioner get changed at the same interval as belt changes. Thats maintenance.

 

[shurguywutt]

I got a low whine on my 2008. I suspect the alternator because the noise doesn't really change when steering left or right. Nothing crazy so it can wait but I will eventually be fixing it.

 

[Snagglefoot]

Now for the rest of the story. We replaced the idler pulley, the alternator and the belt. All good now.

 

[berniedd]

Now that it's off, was it the idler pulley?

 

[Snagglefoot]

Th

Now that it's off, was it the idler pulley?

The Idler pulley and alternator pulley were noisy when turned by hand. We put on a new AC Delco idler pulley and a rebuilt AC Delco alternator. All quiet now.

 

[Snagglefoot]

I’m thinking those are some pretty abrupt turns between the idler pulley and the alternator perhaps causing some tough side loads. This is the third vehicle I’ve had where replacing the alternator alleviated at lot of the squealing noise. For those with more time on their hands replacing the bearings in the alternator may be the ticket.