hey all, so we have a random noise in the 07 Tahoe. When the vehicle is on or the key in the AUX position there is a humming/running noise coming from the headliner area right where the microphone is.

sounds like it could be some sort of ground loop noise or something like that. When you turn the truck off the noise slows down/goes away kinda like a fan motor slowing down.

anyone have anything like this?

 

I did some searching on "other forums" and it may be the air temp fan in that area right above the drivers head in the headliner. I thought the whole time it was the microphone for on star/voice recognition but I guess not. it really sounds like a bad fan motor so I may have to replace it.

 

That would've been my guess as the '07s seemed to have that problem occasionally. If you're friendly w/ your service dept., you might get a "customer appreciation" freeby.

 

so that area is a fan? do go on... i don't have a FSM...

 

ya behind that 'grill" that looks like a speaker is small sensor with a fan to draw air in over the sensor that is part of the auto temp feature. there is one in the back for that part of the system.
I guess when the fan bearings go bad it starts to make noise...part is about $40 from gm parts direct .com. I just hit it real hard with my hand and the noise went away (for now)

 

neato...

 

Also lubing it helps.