whistle noise with AC on?

[CrazyINP]

When I turn the AC on there is whistle noise coming from the engine.
The noise is gone once the AC is turned off.
What could be?

AC is cold no problem.

Thanks

[bimmerboy328i]

Is it like a chirping noise? It's your blower motor.

[LeMansGTS]

normal noise, i have it too

[CrazyINP]

Is it like a chirping noise? It's your blower motor.

It is more like a belt noise.
I might try some belt dresing and if goes away I will replace the belt

[nightkrawler]

or is it a whine like an sc? if so it is probably the ac comp/clutch on its way out. ask me how i know, lol. no ac this summer sorta sucks but i got this funky bmw embroidered sun shield that fits inside the winshield perfectly and comes with a nice gray bag for it. with my discount i think it cost me around $30, but even with out it, its not that expensive. man, does that silly thing cut down the heat inside the car when you get in it after a few hours of hot sun beating down. and it protects the dash/interior, if you have a black gut, go to the dealer and get one of these. works awesome and the price is about the same as what youd pay for a generic pepboys one. plus with tinted windows and that thing in the winshield, it adds a lot of privacy also. just make sure your rear seat is conditioned and soft...

[giterdone]

is the sound almost like a "scratching" noise? I know my m3, my friends 99, and his old 96 328 all did that. It was a subtle noise that only we could hear. I showed a friend it, and I had ot really point it out to him, for him to notice.

[Sinned]

I have that noise and it is the AC compressor clutch assembly...and it doesn't necessarily mean it's on it's way out...but that assembly isn't sealed well plus when our underpanel flies off, more dirt gets in and makes it worse...

[jakeg]

i have the same issue with my car. it sounds like there might be a leaf or something stuck in the blower area causing turbulance? sound will stay with the compressor off. any other ideas? would hate to disassemble the blower for this and try to fault find.
thanks!
Jake

[CrazyINP]

Well,
I found the problem long time ago forgot to update the treat.
It is from the El. fan, so I should replace it soon
the reason I hear it only when the AC is on, is because the fan turns on with the AC.

[jakeg]

ok, makes sense. i thought as much. thanks for clarifying!
Jake