2003 BMW 325 Really annoying whistling sound

ELMO321

MEMBER
2003 BMW 325
6 CYL
AWD
AUTOMATIC
140,000 MILES

I have a high pitched whistling sound that I can't seem to localize where it's coming from. There is no sound when the car is idle or when it comes to a complete stop, but only when it is in motion. Worst off, the sound is irregular, and seems to want to stay quiet when the mechanics take a look at it (gremlins!). It's more noticeable after the car isn't driven for a day or two and then the sound disappears with about 10 min of highway driving.

Monday, December 7th, 2009 AT 6:18 PM

3 Replies

DOCHAGERTY

MECHANIC
9,603 POSTS

Sounds do not travel well in cyberspace, I haven't a clue where to start from your description. Where is it coming from? Has the cyclone separator ever been replaced? Is the check engine light on? Is it causing a driveability issue? Help me help you mate � � �

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Tuesday, December 8th, 2009 AT 9:00 AM

ELMO321

MEMBER
2 POSTS

I don't believe the cyclone separator had been replaced. I think the sound is coming from the engine area. It is more evident when I let go of the accelerator and the car is coasting. It doesn't affect driveability, just really annoying. There are no indicator lights of any kind.

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Wednesday, December 9th, 2009 AT 7:32 AM

DOCHAGERTY

MECHANIC
9,603 POSTS

The sound could also be either the belt tensioner, or deflection pulleys, and possibly the tensioner itself. I agree, it is distracting. Go to Realoem. Com and look for the parts in the engine section, it'll give you an idea of what to expect.

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Thursday, December 10th, 2009 AT 9:29 AM