EXTERNAL COOLANT LEAK FROM ENGINE (HEAD GASKET)

VEHICLES AFFECTED: 1985 - 1986 'M' Car

Some of the subject vehicles having VIN serial numbers prior to JGlMR0851GK713195 (Sprint), JGlMR6859GK812074 (Sprint Plus), JG7MR6852GK860327 (Firefly), JG7MR0857GK760206 (Firefly FE) may experience a loss of engine coolant due to a slight external leak at the cylinder head gasket.

Occurrence of this leak can be identified by examining the front face of the engine cylinder case (in car position) below the cylinder head gasket in the area of the centre cylinder for presence of coolant deposit.

On complaint vehicles the cylinder head gasket should be replaced using new P/N 96055143. Applicable Part Number for cylinder head gasket set is 96055144 and engine gasket set is 96055145.

This new head gasket incorporates revised design features and is a carbon graphite-steel construction for increased resistance to seepage.

Use applicable labour time and operation number.

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.