AC?

[hpt4me]

During an 8 hr drive down south my 2008 Sierra had a whining, like it was a belt, along with a clacking, like some foreign object (cardboard or something) was stuck under the truck. I pulled over... Nothing! And the noise stopped. Again, this happened several times. At first I thought it was a belt, ad maybe air condition related, but it happened again, several hours after the air was off. I still get the clacking more often. The air is on periodically. Someone told me it may be the AC tensioner or the AC "compression valve?"

I had diagnostics run on the AC and it appears to be fine.

 

Any suggestions???

[sahls01gmc]

Have you checked the condition of your belts? How many miles on your truck? Have you replaced tensioners or pulleys yet? Leaking fluids of any kind?

[gmtech4]

Compression valve???????

 

Lmfao !!!!!!

 

Rubbish

[hpt4me]

60k on the truck. Belts all look good. I have not replaced tensioners or pulleys, and there are no leaks.

[sahls01gmc]

I would suspect your pulleys and/or tensioners. See if you can move the tensioners by hand. You shouldn't be able to (unless you are the Incredible Hulk). If you take the belt off the pulleys, check to see if there is any play or goofy sound if you try to spin them.