trainwreck91

I had researched this for a while. And from what I understood is the culprit is the pcv valve. Now usually you can just pop a pcv valve out and drop a new one in. But the chevy engineers decided it would be a good idea to have if permanently mounted to the valve cover???? But I saw that a new cover with valve is around $85-$100. And a couple hours work. So anyone out of warranty and mechanically inclined cans do the repair themselves. Anyhow. Keep us updated on your repair

Ponch

They also put a baffle/windage tray in the oil pan and decarbonize the offending cylinder, or at least that's what the procedure is supposed to be. Here's the TSB:

#10-06-01-008B: Engine Oil Consumption on Aluminum Block Engines with Active Fuel Management (AFM) (Install AFM Oil Deflector and Clean Carbon from Cylinder) - (Mar 7, 2011)


Subject: Engine Oil Consumption on Aluminum Block Engines with Active Fuel Management (AFM) (Install AFM Oil Deflector and Clean Carbon from Cylinder)


Models: 2007-2009 Cadillac Escalade, Escalade ESV, Escalade EXT

2007-2009 Chevrolet Avalanche, Silverado 1500, Suburban, Tahoe

2007-2009 GMC Sierra 1500, Sierra Denali, Yukon, Yukon XL, Yukon Denali, Yukon Denali XL

2008-2009 Pontiac G8 GT

Equipped with Aluminum Block V8 Engine with Active Fuel Management (AFM) (RPOs LC9, LH6, L76, LFA, L92)

with Greater than 45,000 km (28,000 mi)




--------------------------------------------------------------------------------

This bulletin is being revised to add the 2009 model year and new Correction information for the 2009 model year - left rocker arm cover replacement. Information has also been added after step 9. Please discard Corporate Bulletin Number 10-06-01-008A (Section 06 - Engine/Propulsion System).


--------------------------------------------------------------------------------
Condition
Some customers may comment about engine oil consumption of vehicles with higher mileage (approximately 48,000 to 64,000 km (30,000 to 40,000 mi). Verify that the induction system is assembled correctly and that there is no evidence that the engine has been ingesting dirty air due to a mis-assembled induction system. Also verify that the PCV system is functioning properly. If diagnostic procedures indicate that oil consumption is piston/piston ring related, verify that oil consumption is less than 3,000 km (2,000 mi) per liter/quart. If these conditions are met and oil consumption is less than 3,000 km (2,000 mi) per liter/quart, perform the service indicated in this bulletin.

Cause
This condition may be caused by oil spray that is discharged from the AFM pressure relief valve within the crankcase. Under most driving conditions and drive cycles, the discharged oil does not cause a problem. Under certain drive cycles (extended high engine speed operation), in combination with parts at the high end of their tolerance specification, the oil spray quantity may be more than usual, resulting in excessive deposit formation in the piston ring grooves, causing increased oil consumption.

Correction
2009 Vehicles Only
Important: This left rocker arm cover is NOT to be used on 2007-2008 vehicles because of the calibration of the PCV orifice being different in 2007-2008.

A new left rocker arm cover has been released for 2009 engines. Technicians should replace the left rocker arm cover with GM P/N 12642655. This rocker arm cover has relocated PCV drain holes that prevents PCV pullover into the intake manifold. Refer to SI for Valve Rocker Arm Cover Replacement - Left Side.

2008-2007 Vehicles Only


To correct this condition, perform the piston cleaning procedure as described in this document, and install a shield over the AFM pressure relief valve per the procedure outlined in this document. Monitor oil consumption after this repair to ensure oil consumption has improved to acceptable levels. If this repair does not correct the condition, it may be necessary to replace the piston assemblies (piston and rings) with new parts.

Important: It is critical in this cleaning process that the engine/fuel injector cleaner remain in the cylinders for a minimum of 2.5 hours to fully clean the components. The cleaner solution must be removed before a maximum of three hours.

•Verify the oil consumption concern following Corporate Bulletin Number 01-06-01-011F. If oil consumption is found, continue on with this bulletin.
•Remove the spark plugs and ensure that none of the pistons are at top dead center (TDC).
•Clean the pistons by putting 118-147 ml (4-5 oz) of Upper Engine and Fuel Injector Cleaner, GM P/N 88861802 (in Canada, use 88861804), in each cylinder. Allow the material to soak for at least 2.5-3.0 hours, but no more than three hours and then remove the cleaner. A suggested method of removing the cleaner is cranking engine over. Make sure to unplug the ignition coils and fuel injector before cranking the engine over. Also make sure that the painted surfaces are covered so no damage is done.
•Remove the oil pan. Refer to Oil Pan Replacement in SI.

•Remove the AFM valve (1).

•Install the new shield (1), GM P/N 12639759, and tighten the AFM valve to the oil pan to 28 N·m (20 lb ft).
Important: Ensure that the engine cleaner is thoroughly removed before reinstalling the spark plugs. Failure to do so may result in a hydro-lock condition.

•Reinstall the spark plugs. Replace the spark plugs if necessary due to full of carbon. Refer to the parts catalog.
•Reinstall the oil pan. Refer to the Oil Pan Installation procedure in SI. Replace the oil pan gasket if necessary. Refer to the parts catalog. Replace the engine oil if necessary.
•Re-evaluate the oil consumption. Document on the repair order. If the oil consumption is still greater than 0.946 L (1 qt) in 3,200 km (2000 mi), replacement of the pistons and rings will be required.


Important: Some minor scratches may be noticed on the cylinder walls during piston and ring replacement. If the scratch cannot be felt when running your finger nail over it, the scratch is considered normal wear and the block or engine should not be replaced.

Parts Information
Part Number
Description
Qty

12639759
DEFLECTOR-OIL PRESS RLF VLV (quantity of 3 per order) (07-08 Models Only)
1

88861802 (in Canada, use 88861804)
CLEANER, F/INJR 16 OZ LIQUID POUR (Upper Engine and Fuel Injector Cleaner) (07-08 Models Only)
3

12642655
COVER ASM-VLV RKR ARM (09 Models Only)
1

Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
Description
Labor Time

J7555*
Install AFM Oil Deflector and Clean Carbon from Cylinder
3.5 hrs

Install AFM Oil Deflector and Clean Carbon from Cylinder (4WD)
4.5 hrs

Install AFM Oil Deflector and Clean Carbon from Cylinder (G8 Only)
10.5 hrs

J7561
Rocker Arm Cover- Left Bank - Replace- (For 2009 Only)
0.6 hr

*This is a unique labor operation for bulletin use only. It will not be published in the Labor Time Guide.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

Chevrolet Customer Service

Hey Ponch,

Please feel free to reach out to us via private message regarding your dealership visit. We will be glad to document your feedback within our system. In the message please include your full name, contact information, VIN, current mileage, and involved dealership. Thank you.

Kristen A.
Chevrolet Customer Care

Ponch

They performed the 12-06-01-001B and 10-06-01-001J TSB repairs, plus a leaking front differential leak, N/C. Van Chevrolet in Scottsdale stepped up and fixed it. I did have the extended factory powertrain warranty. In this case, it was well worth it. I will definitely consider this dealer for future service and sales.

Chevrolet Customer Service

Hey Ponch,

I'm happy to hear that the dealership has repaired your vehicle issue, and that you had a great experience. Thanks for sharing!

Patsy G
Chevrolet Customer Care

jhersm

I have a 2008 Silverado 5.3L has 114,000 miles has lost 1-2 quarts between oil changes now the stabletrack light has come on with check engine light and rough running, code showed plug # 6 misfire had some oil on it smelled bad replaced and no help compression check on cylinder 6 showed little to no c0mpression, no help from dealer, probably looking at a teardown, truck was very well taken care of, after buying a new 95 grand am, new 2000 S -10, new 2004 Silverado extended cab and a new 2008 Silverado 4 door 4x 4 this has convinced me to look elsewhere for my next vehicle

Ponch

It's probably something you'd want to catch earlier. Have you tried decarbonizing the cylinder? I've never heard of 0 compression. If that's the case, it would be running very badly.

in2pro

Its possible its a broken valve spring....

jhawk7783

________________________

Same or very similar problem on my 2007 Suburban--occurred at approx 135K. Found to be the valve lifter on this active fuel management system engine was stuck in a compressed position. Actually, happened twice. Initially with cylinder #5, and then later with cylinder # 6 (because I should have replaced all active fuel management lifterwith the earlier failure).

If I recall, the active fuel management lifters are on cylinders #3, #4, #5, and #6.

73shark

IIRC, they are 1-4-6-7 that are disabled for AFM. At least that correlates w/ the pic in the brochure.