Any TSB for L99 leaking oil

[shockandawe]

I was going to change my oil before putting car in storage and when I got underneath the car I noticed drops of oil to the rear past the oil filter. Filter and drain plug are tight. I put about 3000 mlies on car this year and it is about 2 quarts low. Anybody know if there are any TSB's?

[barnesql]

Yes, there is. Several people on this forum have had the same problem, as I have, and the dealer fixes it under warranty. It is a crankshaft seal that has gone bad if memory is correct. Relatively minor, it should be fixed in one day. If I can find the service bulletin I will post it, but yeah get it fixed by the dealer.

[Dosin]

I noticed mine leaking oil also on the pavement. I tightened my oil filter and it seemed to stop leaking significantly. This weekend I installed MBRP exhaust and noticed oil around the oil filter when it was on the lift. I think I am going to have the dealer look at my L99. Crankshaft seal?????

[Jayson9]

Does this issue only happen with the 2010's, or is a problem with the 2011's as well? Anybody know?

[shockandawe]

Does this repair involve pulling engine or tranny? I am goig to the dealer tomorrow and it would be helpful to know the TSB, also will they be draining the oil?

[Slowhawk]

From what I've seen alot of times it's the oil cooler.I just tighten the bolts holding it together and it ussually stops the problem. My personal car had 200 miles on it and the cooler was leaking.Got a good 1/2 to full turn on all the bolts.Leak stopped completely. Now every car that is on the lift gets the bolts checked and I'd say 80% of them have oil seeping from the cooler.

[Oldrocker]

TECHNICAL

Bulletin No.: 05-06-01-034L

Date: July 23, 2010

Subject: 5.3L, 5.7L, 6.0L, 6.2L, 7.0L - Engine Oil Leak at Rear Cover Assembly Area (Engine Block Porosity RTV Repair Procedure)

Models:
2004-2007 Buick Rainier
2008-2009 Buick LaCrosse Super, Allure Super (Canada Only)
2005-2011 Cadillac CTS-V
2007-2011 Cadillac Escalade, Escalade ESV, Escalade EXT
2003-2009 Chevrolet TrailBlazer
2003-2011 Chevrolet Corvette
2004-2006 Chevrolet SSR
2005-2011 Chevrolet Silverado, Silverado SS
2006-2007 Chevrolet Monte Carlo SS
2006-2009 Chevrolet TrailBlazer SS, Impala SS
2007-2011 Chevrolet Avalanche, Suburban, Tahoe
2009-2010 Chevrolet Colorado Pickup
2010-2011Chevrolet Camaro
2003-2009 GMC Envoy
2003-2011 GMC Sierra
2004-2005 GMC Envoy XUV
2007-2011 GMC Yukon XL, Yukon Denali, Yukon XL Denali
2009-2011 GMC Canyon
2004-2006 Pontiac GTO
2005-2008 Pontiac Grand Prix GXP
2008-2009 Pontiac G8 GT
2009 Pontiac G8 GXP
2005-2009 Saab 9-7X 5.3i
2008-2009 Saab 9-7X Aero
2003-2010 HUMMER H2
2006-2010 HUMMER H3
with 5.3L, 5.7L, 6.0L, 6.2L, 7.0L VORTEC(TM) GEN III or GEN IV V8 Engine (All Aluminum Block) (RPOs L33, LC9, LH6, LH8, LH9, LM4, LS4, LS1, LS6, L76, L77, LFA, LZ1, LS2, L92, L94, L99, L9H, LS3, LS9, LSA, LS7)

Supercede:
This bulletin is being revised to add the 2011 model year and update the Warranty Information for the Corvette. Please discard Corporate Bulletin Number 05-06-01-034K (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 the engine block and engine rear cover for porosity on the mating surfaces.

- If porosity is found on the engine rear cover (see illustration below), replace the engine rear cover assembly, GM P/N 12633579.
- If porosity is found on the engine block, use the following procedure to apply RTV to repair the engine block porosity.


The porosity issue is in the gasket sealing surface at the top of the cover, near the high pressure oil crossover port. Refer to the picture below. The oil leaks by the gasket and runs down the side of the cover, and may appear to be a leak at the t-joint area of the cover. The fix is to replace the cover with GM P/N 12633579. Also, if porosity is found anywhere on the sealing surface of the engine block, use the following procedure to apply RTV to repair the engine block porosity. Refer to the illustration below.













Important
Clean any residual oil from the block and cover before applying the sealant in the next step.

1. 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.
2. Remove any excess RTV material, especially from inside the high pressure oil passage. Refer to #1 in the above illustration.
3. The joint may be closed immediately after applying the RTV. Total joint time after the RTV has been applied must be under 20 minutes.

Important
Refer to Engine Rear Cover Replacement in SI and follow the tightening specifications and sequence.

4. Reinstall the engine rear cover using a new gasket and a new crankshaft rear main seal. Refer to Engine Rear Cover Replacement in SI.


Parts Information

Important
For Saab (U.S.) only, use P/N 88861206 - Engine Oil Dye (U.S.) or equivalent.







Warranty Information (excluding Saab U.S. Models)

For vehicles repaired under warranty, use:







Warranty Information (Saab U.S. Models)







For vehicles repaired under warranty, use the table.







Disclaimer

[GB EB]

Just had this same problem (crankshaft seal leaking) with my 2011 @ 192 miles. Yes... 192 miles.

Dealer fixed....