A/C COMPRESSOR MOAN ON V-6 EQUIPPED VEHICLES

V-6 ENGINE EQUIPPED

OCCURS WHEN THE A/C COMPRESSOR IS ON. THE MOAN WILL HAVE THE TENDENCY TO GET LOUDER IN HIGHER AMBIENT TEMPERATURES WHEN A/C COMPRESSOR HEAD PRESSURES ARE HIGHER. YOU CAN BEST DIAGNOSE THE SEVERITY OF THE MOAN BY THE FOLLOWING:

A. START ENGINE AND PUT TRANSMISSION IN PARK.

B. WAIT FOR COMPRESSOR CLUTCH TO ENGAGE.

C. INCREASE ENGINE RPM UNTIL NOISE IS MOST AUDIBLE.

D. MOVE LEVER ON CONTROL HEAD FROM LOW TO ECONOMY. THE MOAN SHOULD COME AND GO AS THE COMPRESSOR CYCLES ON AND OFF.

IT MAY BE NECESSARY TO TEMPORARILY ADJUST THE TEMPERATURE DIAL TO PREVENT HI BLOWER OPERATION IN CEONOMY AS BLOWER NOISE WILL LESSEN THE SEVERITY OF THE MOAN.

WHEN INVESTIGATING AN OWNER COMMENT, EVALUATE MOAN AND DETERMINE IF IT IS CONSIDERED NORMAL OR SEVERE.

IF THE NOISE IS SEVERE, THE FOLLOWING PROCEDURE SHOULD BE USED TO IMPROVE THE CONDITION:

1. CHECK A/C HOSES AND CONDENSER FOR A GROUNDING CONDITION. THE HOSE SHOULD NOT BE RESTING HARD AGAINST THE SHEET METAL, ETC. THE CONDENSER MUST BE FREE IN ITS RUBBER MOUNTING AND NOT TOUCHING THE RADIATOR CRADLE.

2. ALL COMPRESSOR MOUNTING BOLTS AND BRACKETS MUST BE WITHIN TORQUE SPECIFICATIONS.

3. BACK OUT THE ADAPTER BRACKET BOLT (REFER TO ILLUSTRATION ON REVERSE SIDE) REMOVE NUT "A", LOOSEN BOLT "B", AND ROTATE BRACKET DOWN. WITH A 1.5 X 10 MM TAP CHASE THREADS IN WELD NUT ON BRACKET TO REMOVE PAINT AND BURRS.

4. REASSEMBLE. REMEMBER, ALL BOLTS MUST BE WITHIN TORQUE SPECIFICATIONS.

5. SET COMPRESSOR BELT TENSION TO SPECIFICATIONS.

6. EVALUATE IMPROVEMENT. IF THIS CONDITION IS NOT SATISFACTORILY IMPROVED WITH THE ABOVE CORRECTION, INSTALL INERTIA RING KIT, P/N 2724034 USING INSTRUCTIONS PROVIDED WITH KIT. COMPRESSOR TO CONDENSER HOSE MUST BE CLEAR OF THE COMPRESSOR PULLEY WITH THE ADDED INERTIA RING AND ALSO MUST BE CLEAR OF THE UPPER SUSPENSION CONTROL ARM.

FOR WARRANTY PURPOSES, USE THE FOLLOWING:

BRACKET REQORK, OPERATION NO. T6037 AT .4 HOUR. INSTALLATION OF INERTIA RING KIT, OPERATION NO. T6038 AT 0.3 HOUR.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.