Interior - Wind Buffeting

GROUP 41
Body

41 02 00

Woodcliff Lake, NJ
Service Engineering

December 2000

SUBJECT:
Wind Buffeting in Vehicle Interior

MODEL:
All

SITUATION:
Customer complaints of wind buffeting inside the passenger compartment associated with certain combinations of open windows or sunroof and vehicle speeds are occasionally encountered.

CAUSE:
This effect is caused by a greater volume of air entering the vehicle interior than can be handled by the interior air exhaust vents. When the volume of incoming air overwhelms the ability of the vents to remove the air, a reverse pressure wave is set up in the vehicle that overcomes the incoming airflow. As the interior pressure drops, the air starts to enter the cabin again until another pressure wave is set up, causing the buffeting effect.

Under certain wind conditions and vehicle speeds, combined with combinations of open sunroof and/or windows, these pressure waves can actually be uncomfortable to vehicle occupants.

This phenomenon is not related to any particular body design, and is not due to any defect, but is caused by operation under certain conditions that exceed design parameters. Generally the complaint of buffeting noise while driving with the sunroof wide open is more prevalent on body design types that feature a hatch back.

CORRECTION:
This pressure wave effect can be minimized or eliminated by changing one of the parameters that cause the effect.

Assuming that the operator wants to maintain a particular vehicle speed, either the volume of incoming air must be reduced, or the ability of the car to exhaust some air must be increased.

-- If the complaint is only with the sunroof open, try closing the sunroof slightly by about 3 inches' or crack open the rear windows.

-- If the complaint is with the front windows open, try cracking open the rear windows, or putting the sunroof in the vent position.

-- If the complaint is with the rear windows open, try cracking open one or both front windows slightly.

-- Installation of an accessory sunroof wind deflector can eliminate or reduce the buffeting on some body styles.

Vehicle speed is an important variable affecting the occurrence of buffeting.

WARRANTY INFORMATION
Information only.