A/C NOISE OR VIBRATION WITH A/C ON (INSTALL KIT)

Model and Year: 1988 C/K TRUCKS WITH AIR CONDITIONING AND 4.3L, 5.0L AND 5.7L ENGINES (VIN CODES Z, H, AND K)

This bulletin is being reissued at this time of year to help Chevrolet dealerships avoid misdiagnosis and possible replacement of good A/C compressors.

Some 1988 C/K trucks with 4.3L, 5.0L and 5.7L engines may exhibit a noise/vibration when the air conditioning is engaged. This noise/vibration is the result of a resonance set up in the serpentine accessory drive system with air conditioning on. If this condition is experienced on 1988 C/K trucks built before the VIN breakpoints listed below, install the following kits. Installation instruction are included with the kits.

Part Number Engine ----------- ------ 10085731 4.3L V-6 With A/C

10085730 5.0L/5.7L V-8 With A/C

All 1988 C/K trucks built after the following VIN breakpoints (last 7 digits) have had the above kits installed at the assembly plants.

Oshawa #2 Chevrolet 1178198

Fort Wayne Chevrolet Z158598

Pontiac East Chevrolet E142329

V-8 Labor Operation

V-6 Labor Operation

V-8 Labor Time

V-6 Labor Time

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.