CYLINDER HEAD GASKET FAILURES CHECK COOLANT SYSTEM

MODELS AFFECTED: 1982-86 SKYHAWKS WITH THE 1.8L OHC L4 ENGINE (VIN CODE O)

Some cylinder head gaskets have been replaced on 1982-86 Skyhawks with 1.8L OHC engines, because of an engine coolant system related condition. Specifically, some cylinder head gasket failures have been accompanied by failed coolant temperature sensors or coolant fan switches. Either of these conditions could expose the cylinder head gasket to excessive temperatures and thermal stresses.

The 1.8L OHC turbo cylinder head gasket, Part No. 90200347, has been designed to accommodate higher stress levels and is less susceptible to the type of failures being encountered, and is recommended as the service replacement for the subject vehicles.

It is recommended that the cooling system temperature sensor and fan switch (Section 8A, Buick Chassis Service Manual) be checked to ensure proper function.

It is essential that the engine be started and run until the thermostat opens; then retorque all cylinder head/cam carrier bolts an additional 30-50 degrees in sequence as shown in the Buick Chassis Service Manual, Section 6A.

Use applicable labor operation and 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.