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For 1990-2009 cars only

Engine Oil Leak - keywords cylinder gasket head intake leak lower manifold oil

Subject:Subject: Engine Oil Leak

Models:2008 Chevrolet Impala, Malibu, Uplander
2008 Pontiac G6
2008 Saturn Aura, Vue
Equipped with 3.5L (LZ4/LZE) or 3.9L (LZ9/LZG/LGD) engines



This PI was superceded to change the administrative details to reflect BQM's inbox. Please discard PIP4452.


The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

Some owners may comment about an engine oil leak.

Follow the diagnosis information in SI. If your diagnosis leads you to believe that the oil leak is coming from either cylinder head gasket then proceed to the next section in this document. However before doing that make sure that the leak is not coming from the "T" joint that is formed where the lower intake manifold, cylinder head and engine block come together. In addition verify that the leak is not coming from the coolant crossover manifold/gaskets that attach to the front of both cylinder heads.

Metro Detroit Dealers:

Do NOT disassemble the engine. Engineering is looking for a vehicle in the "Metro Detroit" (Southeast Michigan) area that exhibits the condition. Dealers in the "Metro Detroit" area that have a vehicle that exhibits the condition should contact Jim Kelly at (586) 492-5612. He will assist in making arrangements for Engineering to review the vehicle at your Metro Detroit area location.

All Other Dealers:

Proceed with repairing the oil leak using the service procedures found in SI.

Recommendation/Instructions:

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.