A/C - Compressor Noise During Hard Acceleration

Group Ref.: HVAC

Bulletin No.: 331224

Date: February, 1994

INFORMATION

SUBJECT:
A/C COMPRESSOR "BRAP" NOISE DURING HARD ACCELERATION

MODELS:
1994 BUICK SKYLARK
1994 CHEVROLET CORSICA AND BERETTA
1994 OLDSMOBILE ACHIEVA
1994 PONTIAC GRAND AM

ENGINE APPLICATIONS:

VIN A - (RPO LGO)
VIN D - (RPO LD2)
VIN 3 - (RPO L40)
VIN 4 - (RPO LN2)

Some owners may express concern with an A/C compressor "brap" noise. This noise may occur under the following conditions:

1. VIN A, D, 3 and 4 engines on wide open throttle acceleration under high A/C compressor head pressure.

2. VIN A, D and 3 engines on key-up once the engine has simultaneously exceeded 2,000 RPM, 20 percent TPS AND vehicle moving 20 mph.

3. VIN A engines with manual transmission when a sudden engine RPM drop from above 6,400 engine RPM to below 4,200 engine RPM occurs.

The A/C compressor is calibrated to disengage under any one of these conditions. Upon reengagement of the compressor clutch, above 3,800 engine RPM, a "brap" noise may be created by the wobble plate regaining speed and reinstating normal A/C system pressures.

Under the above conditions, a compressor "brap" noise is considered to be normal.