['99 M3] Acceleration "Squeal"

["Hughes Photo" <scott@xxxxxxxxxxxxxxx>]

Greg, I hope you figure out what's up as I'm experiencing something similar
with my '99 M3.

I can't pinpoint when this squeal appeared, but I also have a CAI, this one
is a PAR.

My squeal appears upon moderate acceleration (in gear/under load) at engine
speeds of ~2000 - 3000rpm. Light or heavy throttle does not cause the noise.
Initially, I thought it was a brake noise, as it sounds similar to the
'screech' from some disc brakes, the pitch does not vary in frequency as
engine increases.

Any thoughts from members would be appreciated.

Although I have been reading this digest for some time, this is my first
posting here... hope I did it correctly!  -Scott

> Date: Sun, 25 Aug 2002 19:35:38 -0400
> From: "Gregory F. March" <march@domain.elided>
> Subject: ['99 M Roadster] Squeel from driver's front, Part Duex
>
> Hi folks, sorry for cross posting...
>
> You may recall my email a while ago (I've appeneded it to the end of
> this message).
>
> Well, I had it into the dealer and the chief mechanic listened to
> it. They replaced the belt tensioner pully, but the sound remained. He
> claimed that it could be the sound of air flowing through the intake
> and since I had a Conforti CAI, the sound would be much louder.
>
> I made a second appointment to try to diagnose the problem with the
> stock airbox on. To my surprise, when I put the stock airbox on, I
> could not reproduce the squeel.
>
> Does this make sense to anyone? Believe me, this sound *really* sounds
> like metal on metal and I am having a hard time understanding how the
> intake can make that noise. Is the stock airbox just masking the
> problem? It there something in the intake system that moves that could
> make a squeel?
>
> I am totally stumped. Any help would be greatly appreciated.
>
> Thanks!
>
> /greg
>
>
> On Aug 4, 2002, "Gregory F. March" <march@domain.elided>  wrote:
>
>  |OK, I'm stumped.  I've got a squeel coming from the driver's front
>  |side that I can't figure out.  I've replaced pads and rotors, so I'm
>  |pretty confident that isn't the problem.  I'm going to bring it in to
>  |the dealer, but I'd like to go in armed with knowledge.  Fortunately,
>  |the sound is consistently reproducable, and easy to describe, but if
>  |the test driver doesn't have patients and follow the instructions
>  |exactly, the sound will not occur.
>  |
>  |Here's how I reproduce it.  In any gear at around 1500rpm at constant
>  |acceleration, very gently and slowly accelerate harder and harder (you
>  |never need more than 1/4 throttle though) and you will hear a squeel.
>  |When you reach the "sweet spot" in terms of acceleration, the squeel
>  |is constant.  A little more or a little less throttle and it goes a
>  |way.  Using the brakes while the noise is occuring has no effect on
>  |the sound.
>  |
>  |Everything "looks" okay under the car (sway bars are tight, steering
>  |linkage has no play, etc).
>  |
>  |Could this be a wheel bearing?
>
>
> - --
> Gregory F. March    -=-    http://www.gfm.net:81/~march    -=-
> AIM:GfmNet
>
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>
> End of bmw-digest V9 #2220
> **************************

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