COLD ENGINE PISTON KNOCK ON 2.OL (NEW PISTON)

MODELS/YEARS 1987-88 FIRENZA

Some customers may comment of a cold engine knock at initial vehicle start-up. This condition may be repaired by installation of tighter fitting pistons available through service parts:

Part Number 101 12367 0.04mm O.S. Part Number 101 12368 0.50mm O.S. Part Number 101 12369 1.00mm O.S.

Parts are currently available from GMSPO.

Piston fit should be reduced to .0008" - .0015" clearance. The cylinder block may need to be honed to achieve the desired piston fit. Refer to the Service Manual Section 6A for proper piston fit instructions.

WARRANTY INFORMATION

Labor Operation Number: J1308

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.