Engine - Cold Knocking Noise

91buick08

Bulletin: 91-6A-11
Date: Nov. '91
Ref. No.: 91-260-6A
Corp. Ref. No.: 136515R


SUBJECT: PISTON SCUFFING - 3.1L ENGINE (REPLACE A PARTIAL ENGINE - NOT PISTON)

MODELS AFFECTED: 1989-90 REGALS WITH 3.1L V-6 ENGINE (VIN CODE T)


CONDITION:

Some 1989-90 Buick Regals with 3.1L engines (VIN Code T) may exhibit engine piston scuffing, which could result in cold engine knock at low ambient temperatures. This condition will not lead to engine failure and is limited to cylinders # 2, # 4 and # 6.

CAUSE:

Premature wear of the pistons due to low adhesion of the tin plating.

CORRECTION:

If pistons need replacement due to scuffing, a partial engine replacement is HIGHLY recommended rather than replacement of individual pistons. This recommendation is made since other pistons in these engines might have to be replaced later.

WARRANTY INFORMATION:

Labor Operation Number: J1820
Labor Time: Use applicable time