Suspension - Front End Droning/Whistling Noises

SI B 37 03 09
Special Suspension Systems

October 2009
Technical Service

SUBJECT
Droning or Whistling Noise from Front Axle Area

MODEL
F01, F02 (7 Series) produced from 8/31/08 to 3/24/09 equipped with option code 229 Dynamic Drive

SITUATION
The customer may report a droning or whistling type of noise from the front axle area, which occurs while driving on uneven road surfaces. The noise may be amplified when turning the steering wheel.

Due to hydraulic pulses which occur during activation of the Anti-Roll Stabilization system (ARS), a noise from the ARS valve block may occur.

CORRECTION
Install the hydraulic pressure line with integrated control orifice at the ARS valve block.

PROCEDURE
The noise described in this bulletin emanates from the ARS valve block. The noise can be identified by using an electronic listening device to isolate the source of the noise. If the ARS valve block is not the
source of the noise, continue normal troubleshooting. If the valve block is the source of the noise, then the pressure hose must be replaced. Refer to Repair Instruction RA 37 13 127, "Removing and installing/replacing pressure line for valve block short".





PARTS INFORMATION





WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty.





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