A/C COMP. NOISE/VIBRATION PUMPING NOISE DURING IDLE

VEHICLES AFFECTED: 1984 and 1985 'J' Models

CONDITION:

---------- Air conditioning compressors may make a pumping noise during idle and low speed road conditions with the A/C 'ON'. The sound generally comes from the engine compartment and can be heard in the passenger compartment as a growl sound.

During maximum cooling demand (high ambient temperatures, 'norm' A/C model selection, and after high blower fan use), compressor pulsation noise is more pronounced.

CAUSE:

----- Compressor pumping of refrigerant results in pressure pulses that are transmitted in the suction and discharge hose assemblies.

CORRECTION:

---------- I. 1984 MODEL YEAR:

Replace the original lightweight compressor assembly with compressor assembly part number 12300849 and Inertia Ring Kit part number 2724034. The inertia ring kit is a bolt-on style and can be easily installed in the dealership. Mounting instructions are included in the kit.

Use the most applicable labour operation from the Canadian Labour Time Guide and claim 1.6 hours.

II. 1985 MODEL YEAR:

Most noise can easily be eliminated by bending both the suction (low pressure side) and the discharge (high pressure side) pipes at the compressor attachment (see illustration).

NOTICE:

The lines should be moved no more than 6.0mm (1/4 inch) in any direction. Care should be taken not to break, crack, or dent the pipes nor allow the hoses to make contact with each other.

Should the noise level continue in the car, remove the lower tie bar clip and screw at the lower radiator support area. Be certain that the hoses do not contact each other.

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.