ENGINE NOISE WORN PISTON PIN

MODELS AFFECTED: 1985-1986 CIMARRONS WITH 2.OL ENGINES

Some 1985-1986 Cimarrons equipped with 2.OL L4 engines may experience a knock-type engine noise. If this noise is identified as a crank speed internal reciprocating noise, the source may be caused by wear to the piston pin boss of the piston.

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 pistons and pins.

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 affected cylinder:

Standard Piston/Pin Assembly P/N 10103570 High-Limit Piston/Pin Assembly P/N 10103571 0.5mm Oversize Piston/Pin Assembly P/N 10103572 l.Omm Oversize Piston/Pin Assembly 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.OL engines.

For warranty purposes, use Labor Operation J1308 at 5.4 hours to replace one piston with an add time of .7 hour to replace each additional piston.

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.