525it "whistling"...ideas?

[Jjcarr]

Got an issue with my 95 525it (automatic). When in drive, with no power and the brake on, there's a "whistling" noise comming from under the hood. In park it doesn't do it, and when moving it doesn't do it either. Almost sounds like a belt slipping or something. Since I can't hear it in Park I can't pop the hood and locate it. Ideas?

[BillionPa]

may be the ICV, or a vacuum leak, is your idle ok?

[Jjcarr]

may be the ICV, or a vacuum leak, is your idle ok?

Yeah, idles, starts, runs, etc... perfectly.

[Ross]

Chock the wheels or pull it against a wall so you can listen.

[Omega]

Can you hear it in neutral or it it only when the engine is under load?

If only under load get someone else to sit in the car in Drive with their foot on the brake and the hand (emergency) brake locked on. Also, stand to the SIDE of the car, not in front (difficult unless you're over 8' tall as the bonnet is in the way... ) and most certainly do not lie underneath unless you have a particularly tasty 525 and your estate would be willing to sell it to me for a song....

If it helps, I would expect a whistling noise to be vacuum related.

[Jjcarr]

Nah, only when it's in park with the brake on and no pressure on the accelerator. As soon as I step on the gas and start moving it stops.

[Bryson]

sounds to me like a vacuum leak somewhere before the throttle body, or an exhaust leak. Take it to an independent mechanic and ask if he has any quick ideas if you can't figure it out.

Does it get much louder when you rev up the motor?

[HDhandyman]

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