07 yukon with whistle from dash

[69charged]

hello all. i have my 07 yukon whistling at me all the time!!
it sounds like a vacuum leak under the dash somewhere around the center area. only hear it at a stop light when my foot is on the brake and i am in gear. its tone changes slightly too. like kinda going up and down. it is so annoying that i think i might tear the dash apart just to find it. anyone else have this problem or heard of what might cause it??
thanks
clarence

 

[KMeloney]

It's not your Nav disc searching (assuming you have Nav), is it?

 

[fishhunter911]

I have the same thing. Sounds like a alternator whine due to a bad ground somewhere. Just haven't had time to dig into mine yet.

 

[edgaranah1]

Weird mine does that too. Although mines isnt that loud i thought it was just the stereo. And the alternator does whine but only when i step on the gas its really annoying.

 

[GM Customer Service]

Please keep us posted when the issue has been taken care of.

Thank you,
Caron, GM Customer Service

hello all. i have my 07 yukon whistling at me all the time!!
it sounds like a vacuum leak under the dash somewhere around the center area. only hear it at a stop light when my foot is on the brake and i am in gear. its tone changes slightly too. like kinda going up and down. it is so annoying that i think i might tear the dash apart just to find it. anyone else have this problem or heard of what might cause it??
thanks
clarence

 

[69charged]

no i dont have nav. it is deffinitely a vacuum leak because it changes pitch. some times it changes frequently, like as fast as a turn signal. other times its steady until i give it throttle to move ahead, then it goes away. one thing i have to try tonight is to change the damper positions and see if it goes away. then maybe i can narrow it down to a certain setting.
or, maybe its not a leak at all but a noise from the vacuum system that cant be fixed. either way i intend to find that annoying bugger!!
does anyone have access to a parts diagram of the hvac system for the front??
clarence

---------- Post added at 04:26 PM ---------- Previous post was at 04:23 PM ----------

i will say this though. it seems to have gotten worse with the warmer weather. i just bought this yukon in december and now that it is spring, its getting worse. or i am listening for it more.