Sierra 1500 4WD V8-6.0L (2007)
Oil Pressure Regulator Valve: All Technical Service Bulletins
Engine - Oil Consumption On Aluminum Block Engines
TECHNICAL
Bulletin No.: 10-06-01-008B
Date: March 07, 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)
Supercede:
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.
1. Verify the oil consumption concern following Corporate Bulletin Number 01-06-01-011F. If oil consumption is found, continue on with this
bulletin.
2. Remove the spark plugs and ensure that none of the pistons are at top dead center (TDC).
3. 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
