Need help locating an air compressor like noise; no, i don't have auto ride

[01SLE]

This is driving me crazy... I have an 2001 Yukon SLE 5.3 4x4. When the vehicle is running and you're in the cab, an air compressor like noise is very audible. When I turn the vehicle off, the sound slows and stops after the engine stops. It sounds like a weak/small air compressor which is venting to atmosphere. As if I had that little auto ride compressor on the rear frame and it was airing up nothing at all; just running none stop.

But I don't have the Z55 auto ride option. I have the ZW7 smooth ride option and G65 auto level option. No compressor on the frame, no air or electrical lines to the shocks.

When I'm sitting in the drivers seat I can't tell if it's coming from the front of the cab or rear. I can't really hear it from outside or under the hood. No diagnostic lights, no unfavorable driving characteristics. Just an annoying damn noise!!!

 

[chevync]

Above your head while in the drivers seat there is a small vent with a fan in it (looks like a speaker vent), sometimes the fan will vibrate, took me forever to figure it out on mine.lol

 

[clandr1]

Above your head while in the drivers seat there is a small vent with a fan in it (looks like a speaker vent), sometimes the fan will vibrate, took me forever to figure it out on mine.lol

+1. It's the ambient air temp sensor that works w/ your A/C & heat. I hit mine with a couple of bursts of compressed air, and it fixed the problem. Sometimes they get dirty and make noise. If the compressed air doesn't fix it, you may need a new one (sometimes the bearings go out).

 

[ezdaar]

use a needle and stick it into the holes on the cover. DONOT just blast comp air into the cover.
It will over spin the blades and nuke the bushing.

So hold it still with needle and work your way around the cover with comp air.

 

[NathanJax]

http://www.tahoeyukonforum.com/forum/showthread.php?t=4859

 

[01SLE]

Thanks for the info people. I'll try this tomorrow.

 

[1989toddm]

We just bought an 01 yukon that does this very thing..thanks guys!! So glad to know what that little noise is.

 

[ccd_1606]

Mine does the same thing but I narrowed it to the passengers rear area. I think it's something with the rear heat and air. It's only audible with the key on even if the blower is off.