Horrible Noise

[Kolby07]

I have an 02 LS V8 that makes a terrible whining noise when I turn on the air and goes away about 10 minutes after turning it off again. I've had it checked out and all thought it was the power steering but turns out thats not the case. nobody can give me a strait answer as to what it is... any ideas?

 

[joegr]

Wild guess - AC expansion valve.
I would've guessed the belt, but that should stop as soon as you turn the AC off.

 

[SoonerLS]

You might check the pump for the cooling fan (the one that draws air through the radiator). The 1st Gen LS has a hydraulically-driven fan, and, IIRC, turning on the AC is supposed to kick it up to high speed--and it makes sense that it would stay there even after the AC is disengaged.

 

[Mechanicboy]

...goes away about 10 minutes after turning it off again.

After you turn off the A/C or the engine? If the you are only turning the A/C but leaving the engine running then it could be the engine fan.
You said you thought it was the PS pump so I'm taking it that the noise is coming from the engine compartment and not inside the dash?

 

[Soopa009]

Hey buddy mine started doing the same thing about a month ago as well.. If he has the same problem as me like soon as I turn the car on it sometimes makes that noise like a real whine, then after a little bit it will go away.. but say if its whining the first 10 mins i turn the ac off it will go away. Never tried turning the engine off but either way I think we both have the same problem.. Sorry I havent found the solution yet :-(

 

[tireman]

hydraulic fan pump

That pump will make a heck of a loud noise then fade as it warms up and gets lubricated. Open the hood and have someone do the a/c stuff and listen to the pump closely.