ENGINE OVERHEAT WITH SNOWPLOW IN UP POSITION

Model and Year: 1988 C/K TRUCKS WITH 5.7L (VIN CODE K) ENGINE AND UPFITTED WITH SNOWPLOWS

Some 1988 C/K trucks with 5.7L engines and upfitted with snowplows may experience an engine overheat condition while driving with the plow in the "up" position. This condition may be indicated by one or both of the following indications.

Trucks Without Gages

Engine temperature light comes on, then an audible noise is heard ("Roar" - due to fan clutch engagement) and then the temperature light goes out.

Trucks With Gages

Check gage light comes on at about 235 degrees F and the engine temperature continues to climb to the 250 degree F mark, an audible noise is heard ("Roar" - due to fan clutch engagement) and then the temperature returns to a normal indication 205 - 215 degrees F.

If these conditions are encountered on trucks with or without gages, they can be repaired by replacing the fan clutch with P/N 15550738.

NOTICE: On vehicles with gages, the check gages light was designed to activate at 245 degrees F. On vehicles built prior to the breakpoints listed, however, the light is activated at 235 degrees F. If this presents a problem in certain customer applications, the gage cluster can be updated by contacting your AC repair center and obtaining a cluster that has the new check gages resistor.

Vehicles built after the VIN breakpoints listed below include the 245 degrees F check gages resistor.

Pontiac - JE 164595

Fort Wayne - JZ 200778

Oshawa - J1 123424

Remove the cluster using procedures in Section 8C - Instrument Panel and Gages of the 1988 C/K Service Manual.

Install the new cluster.

Vehicles built after the VIN breakpoints listed below include the new fan clutch.

Pontiac - JE 166664

Fort Wayne - JZ 211190

Oshawa - J1 230424

Labor Op J3390 - Clutch Assembly Fan Labor Time: - 0.3 Hr

Labor Op N4192 - Replace Instrument Cluster Labor Time: - 0.4 Hr

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.