Engine - Overheats When Fitted With a snow plow
88chevy12Number: 88-177-6B
Section: 6B
Date: March, 1988
Subject: ENGINE OVERHEAT
Model and Year: 1988 C/K TRUCKS WITH 5.7L (VIN CODE K)
ENGINE AND UPFITTED WITH SNOWPLOWS
TO: ALL CHEVROLET DEALERS
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