Engine - Knock At Initial Start-Up
89chevy31Number: 89-242-6A
Section: 6A
Date: August 1989
Corporate Bulletin No.: 936120
Subject: COLD ENGINE PISTON KNOCK
Model and Year: 1987-89 J AND L CARS WITH 2.0L ENGINE
TO: ALL CHEVROLET DEALERS
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 0.04 mm O.S.
P/N 10112368 0.50 mm O.S.
P/N 10112369 1.00 mm 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