ENGINE NOISE WORN PISTON PIN

ENGINE NOISE CAUSED BY WORN PISTON PIN

VEHICLE AFFECTED 1985-86 J-CAR WITH 2.0L L-4 ---------------- (RPO LQ5; VIN CODE P)

A customer comment of engine noise that is identified as an internal reciprocating noise may or may not be caused by a worn piston/piston pin interface.

If the piston is suspected of causing a cold and hot noise complaint, then the piston/piston pin interface should be examined for wear, i.e., out-of- round or grooving. The service manual procedures in Section 6A should be followed for removal and inspection of the piston and pin.

If wear conditions indicate a need for piston and pin assembly replacement, then one of the following new piston and pin assemblies should be used for the respective cylinder:

Standard Piston/Pin Asm. = P/N 10103570 High-Limit Piston/Pin Asm. = P/N 10103571 0.5mm Oversize Piston/Pin Asm. = P/N 10103572 1.0mm Oversize Piston/Pin Asm. = P/N 10103573

Select the piston/pin assembly by using the procedure described under "Piston Fitting" in Section 6A of the service manual for 2.0L engines.

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.