PROM - Cold Engine Knocking Noise
90chevy02Number: 89-284-6E
Section: 6E
Date: December 1989
Corporate Bulletin No.: 936528
Subject: COLD ENGINE KNOCKING NOISE
Model and Year: 1989 B CAR WITH 5.0L (VIN CODE E) ENGINE FEDERAL EMISSIONS ONLY
TO: ALL CHEVROLET DEALERS
Some owners may comment of a cold engine knocking noise. This noise may be misdiagnosed as piston slap resulting in unnecessary engine replacement.
The noise may be caused by detonation at ambient temperatures less than 40 degrees F (4 degrees C). Refined spark control tables in a new PROM specifically address this detonation condition.
Replace the PROM with the part number below:
New Part Number Broadcast New Scanner ID
16148142 ATYR 8031
Parts are currently available from GMSPO.
Labor Operation Number: T0500
Labor Time: .5 hours