Engine - Excessive Oil Consumption (Valve Stem Seals)

91buick06

Bulletin: 88-6-28A

Date: June '91

Ref. No.: 88-307-6

Corp. Ref. No.: 836114R


SUBJECT: EXCESSIVE OIL CONSUMPTION (INSPECT INTAKE VALVE STEM SEALS)

MODELS AFFECTED: 1988 CENTURY MODELS WITH 2.5L ENGINE (VIN CODE R)
1988 SKYLARK MODELS WITH 2.5L ENGINE (VIN CODE U)





THIS BULLETIN REPLACES SERVICE BULLETIN 88-6-28 WHICH MAY BE DISCARDED.

Some customer comments may be received regarding excessive engine oil consumption. "Excessive" oil consumption may be defined as approximately 1000 miles per quart or less. Light blue-colored exhaust smoke may or may not be evident in these cases due to the catalytic converter's exhaust gas processing.

This oil consumption condition may be caused by one or more damaged intake valve stem seals.

NOTE: It is recommended that intake valve stem seal inspection be performed first in diagnosing reported cases of excessive engine oil consumption.

An inspection of the valve stem seal of any cylinder will reveal if the seal is in fact damaged. The damaged seal(s) can be identified by a cutout section on the top portion of the seal, see Illustration. Valve spring removal is required to properly inspect the seal. If the seal is identified as damaged, all intake valve stem seals must be replaced with P/N 10042875. Refer to Section 6A1 of the Service Manual for details on seal servicing.

Parts are currently available from GMSPO.

If the intake valve stem seal inspection for all cylinders does not reveal any damaged seals, then the cause of the excessive oil consumption is in some other area of the engine.

Use applicable labor operation and time per the Labor Time Guide.