Excessive Engine Oil Consumption (Verify Condition, Inspect Valve Stems, Replace Cylinder Head(s) If Necessary)
| 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:
Do This | Don't Do This | ||||
|---|---|---|---|---|---|
| Do NOT replace engine assembly or build up cylinder heads with SPO material. |
Important: 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 below.
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
WPC # | P/N | Description / Usage |
|---|---|---|
374 | 12589777* | Cyl Head Asm (RPOs L33, LMG, LY5, LH6, LS4, LC9) |
375 | 12589776* | Cyl Head Asm (RPOs LR4, LM7, L59) |
*Cylinder heads completely built-up are available at the GM Warranty Parts Center (WPC). Fax the form included in this bulletin to the WPC.
Warranty Information (excluding Saab U.S. Models)
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
J0510 | Head, Cylinder-Right Bank - Replace | Use Published Labor Operation Times |
J0511 | Head, Cylinder-Left Bank - Replace | |
J0517 | Head, Cylinder-Both Banks - Replace |
Warranty Information (Saab U.S. Models)
For vehicles repaired under warranty, use:
Labor Operation | Description | Failed Object | Fault/Reason Code | Location Code | Warranty Type | Repair/Action Code | Labor Time |
|---|---|---|---|---|---|---|---|
2110001 | Head, Cylinder-Right Bank - Replace | 21100 | 71 | 4 | 01 | 01 | Use Published Labor Operation Times |
2110002 | Head, Cylinder-Left Bank - Replace | 21100 | 71 | 3 | 01 | 01 | Use Published Labor Operation Times |
2110003 | Head, Cylinder-Both Banks - Replace | 21100 | 71 | 3 | 01 | 01 | Use Published Labor Operation Times |
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.
Parts Request Form - Warranty Parts Center |
|---|
To: Warranty Parts Center e-mail: [email protected] or WPC Fax: 248-371-0192 Attn: Jeannette Dunn
Part Being Requested: Quantity one of WPC #374 _____ Quantity two of WPC #374 _____ Quantity one of WPC #375 _____ Quantity two of WPC #375 _____
Dealer BAC (U.S.) / Dealer Code (Canada):
Dealer Name:
Dealer Address:
Dealer Contact Person:
Dealer Phone Number:
Repair Order Number:
Vehicle VIN:
Important: If you do not receive the part within 2 business days after e-mailing or faxing your part request to the Warranty Parts Center, please call Customer Assistance at 248-371-9901/9902. 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. |
