Engine - Abnormal Noises

Bulletin No.: T-93-116
File in Group: 6
Number: 47
Corp.Ref.No.: 316007
Date: July, 1993

SUBJECT: ENGINE NOISES

MODELS AFFECTED: 1993 CADILILACS

Some 1993 vehicles with 4.6L engine may exhibit abnormal engine noises. The first noise can 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.