INFORMATION ON ENGINE NOISES

SUBJECT: INFORMATION ON ENGINE NOISES

VEHICLES AFFECTED: 1993 "C/D/E/K/V" MODELS

THIS BULLETIN SUPERSEDES AND REPLACES CORPORATE BULLETIN REFERNCE NUMBER 316007.** THIS BULLETIN IS BEING REVISED TO CHANGE THE CANADIAN BULLETIN NUMBER FROM 93-6-120 TO 93-6-123.

Some 1993 C/D/E/K/V vehicles with 4.6L engine may exhibit abnormal engine noises. The first noise ran be characterized as a "piston slap" type noise which is noticeable for a short time after the engine is started from a cold condition. This noise diminishes and will disappear completely as the engine warms up. The second noise is best described as sounding like a hydraulic valve lifter "tick". While this noise may also be exhibited after starting, it may or may not disappear after the engine warms and sometimes will come and go.

Neither of these noises will affect the long-term durability of the engine and no attempt should be made to repair or replace engines for these conditions. When the repair information is available, a Service bulletin will be issued.

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.