Rear main seal?
2007 impala SS
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Engine - Oil Leak From Rear Cover Assembly Area
Bulletin No.: 05-06-01-034E
Date: February 12, 2007
TECHNICAL
Subject:
5.3L LC9, LS4, L33, LH6, LM4, 5.7L LS1, LS6, 6.0L LS2, L76, 6.2L L92, 7.0L LS7 - Engine Oil Leak at Rear Cover Assembly Area (Engine Block Porosity RTV Repair Procedure)
Models:
2004-2007 Buick Rainier
2005-2007 Cadillac CTS-V
2007 Cadillac Escalade, Escalade ESV, Escalade EXT
2003-2007 Chevrolet Corvette, TrailBlazer
2004-2006 Chevrolet SSR
2005-2007 Chevrolet Silverado, Silverado SS
2006-2007 Chevrolet Impala SS, Monte Carlo SS, TrailBlazer SS
2007 Chevrolet Avalanche, Suburban, Tahoe
2003-2007 GMC Envoy, Sierra
2004-2005 GMC Envoy XUV
2007 GMC Yukon XL, Yukon Denali, Yukon XL Denali
2004-2006 Pontiac GTO
2005-2007 Pontiac Grand Prix GXP
2005-2007 Saab 9-7X
with 5.3L, 5.7L, 6.0L, 6.2L, 7.0L VORTEC(TM) GEN III or GEN IV V8 Engine (RPOs LC9, LS4, L33, LH6, LM4, LS1, LS6, LS2, L76, L92, LS7)
Supercede:
This bulletin is being revised to update warranty information. Please discard Corporate Bulletin Number 05-06-01-034D (Section 06 - Engine/Propulsion System).
Condition
Some customers may comment on an engine oil leak.
Cause
Upon initial diagnosis, it may be determined that the leak is coming from the rear cover gasket. This condition may be caused by engine block porosity on the sealing surface. This issue pertains to aluminum block applications only.
Correction
Follow the steps for Oil Leak Diagnosis in SI to determine the source of the leak. If the leak has been diagnosed as coming from the engine rear cover assembly, refer to Engine Rear Cover Replacement in SI and remove the engine rear cover assembly. Inspect for engine block porosity where the engine rear cover mates to the engine block. If porosity is found anywhere on the sealing surface, use the following procedure to apply RTV to repair the engine block porosity. Refer to the illustration below.
Clean any residual oil from the block and cover before applying the sealant in the next step.
Wipe a small amount of RTV, P/N 12378521 (in Canada, use P/N 88901148), onto the surface using a plastic scraper to fill the porosity.
Remove any excess RTV material, especially from inside the high pressure oil passage. Refer to # 1 in the above illustration. The joint may be closed immediately after applying the RTV. Total joint time after the RTV has been applied must be under 20 minutes.
Refer to Engine Rear Cover Replacement in SI and follow the tightening specifications and sequence.
Reinstall the engine rear cover using a new gasket and a new crankshaft rear main seal. Refer to Engine Rear Cover Replacement in SI.
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