Flutter Noise in air induction under aceleration
 

Having had success finding answers to technical questions on the Porsche side of the board, I thought I would try to get an answer to a technical question on the BMW side.
I had an oppurtunity to ride in a 96..? 850csi yesterday and listened when the owner pointed out a noise...under acceration.....a flutter noise almost like a flap or induction door was flapping as rpm's increased....

He was told by his service guy, that they would have to remove the dash for a $grand$.....to fix the problem....
It's hard to believe thet the dash has to come out, but will wait for somone else's experience or advise.....

The noise seems directly affected/ caused by aceleration....and doesn't sound like it in the dash, more in the engine air induction ducting....maybe one of the noise baffles....?

Any help would be appreciated....

I'm not sure about the 8 series cars but the 7 series has 2 flapper doors that open when you drive to provide fresh air to the system. Some people prop them open all the time to allow for fresh air in the A/C system when sitting still. On a 7 series the doors are at the back top of the engine compartment.

Thanks for the input....
At least we know that something like a flapper door exists, now to find it on the 850...

wess

Its caused by the baseball card thats held to the wheel by a clothspin. The previous owner probably forgot to remove it when he sold it.

Nah!
First thing I checked!
Definately in the induction.....