Engine - Excessive Oil Consumption
Bulletin No.: 07-06-01-007Date: April 16, 2007
TECHNICAL
Subject:
Excessive Engine Oil Consumption (Verify Condition, Inspect Valve Stems, Replace Cylinder Head(s) if Necessary)
Models:
2006-2007 Chevrolet Avalanche, Silverado Classic
2007 Chevrolet Impala, Monte Carlo, Silverado, Suburban, Tahoe, TrailBlazer
2006-2007 GMC Envoy, Sierra Classic
2007 GMC Sierra, Yukon
2007 Pontiac Grand Prix
2006-2007 Saab 9-7X
with 5.3L V8 Engine (VINs B, Z, 3, M, T, 0, V, C, J - RPOs L33, L59, LC9, LH6, LM7, LMG, LR4, LS4, LY5)
Condition:
Some customers may comment on excessive engine oil consumption. The rate of oil consumption described may usually be around 0.946 liter (1 quart) of engine oil in 805 to 1125 km (500 to 700 mi).
Cause
The engine oil consumption may be caused by a nick in the valve stem.
Correction:
The completely built-up cylinder heads can be obtained from the Warranty Parts Center.
Complete the current SI diagnosis for any DTCs or symptoms found. Refer to Corporate Bulletin Number 01-06-01-011C for Information on Engine Oil Consumption Guidelines.
If excessive oil consumption has been verified, all of the valve stems need to be inspected for damage. One or more of the valve stems may be nicked.
It is possible to see a nicked valve stem through the valve spring coil, but in some cases the valve spring may need to be removed. Photos of a nicked valve stem are shown.
If the engine oil consumption is excessive, and a nicked valve stem has been found, the cylinder head will need to be replaced. The cylinder head will be serviced as an assembly (the head will be complete with valves and springs) and shipped to the dealer by the Warranty Parts Center (WPC). Old cylinder heads will be requested and sent back to the WPC. The dealer will have to order the necessary parts/gaskets to complete the cylinder head remove and replace. If the valve stem nicks were found on only one cylinder head, only that cylinder head is to be replaced. Refer to the Cylinder Head Replacement procedures in the applicable Engine Mechanical sub-section.
The Julian date is part of the cylinder head serial number. The serial number is located at the right hand end of the exhaust face. If looking directly at the cylinder head exhaust ports (exhaust manifold mounting face) the serial number will be just above and right of the farthest right exhaust port. The first digit of the serial number is the calendar year. The second, third, and fourth digits are the Julian date.
Parts Information
Warranty Information (excluding Saab US Models)
For vehicles repaired under warranty, use the table.
Warranty Information (Saab US Models)
For vehicles repaired under warranty, use the table.
IMPORTANT NOTE WHEN PRINTING THIS FORM: If the form prints out on two pages, make certain you fax BOTH pages so that the WPC receives all the needed information. Missing information will delay or prevent the part from being shipped.
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