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:
P/N 10112367 0.04mm O.S. P/N 10112368 0.50mm O.S. P/N 101 12369 1.00mm O.S.
Parts are currently available from GMSPO.
Piston fit should be reduced to .0008" - .0015" clearance. The cylinder case may need to be honed to achieve the desired piston fit. Refer to the Service Manual Section 6A-20 for proper piston fit instructions.
Labor Operation Number: J1308 Labor Time: 5.4 Hours
Add: .3 With Automatic Transmission
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.