S10/T10 Blazer 2WD L4-151 2.5L (1988)
Valve Guide Seal: All Technical Service Bulletins
Engine - Damages Valve Seals Causing Oil Consumption
Number:
88-447-6A
Section:
6A
Date:
MAY 1991
Corp. Bulletin No.: 836114R
Subject:
EXCESSIVE OIL CONSUMPTION
Model and Year:
1988 CELEBRITY S/T TRUCK AND M VAN WITH 2.5L ENGINE
THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 88-446-6A, DATED APRIL 1991. THE VERBAGE IN
THE FOURTH AND SIXTH PARAGRAPHS HAS BEEN CHANGED TO ALL CYLINDERS. ALL COPIES OF 88-446-6A SHOULD 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 intake 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 a 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.
