Base Engine Misfire with Excessive Oil Consumption

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

Cause	Correction
Worn valves, valve guides and/or valve stem oil seals	Inspect the spark plugs for oil deposits. Refer to Spark Plug Inspection in Engine Controls - 3.5L (L66). Repair or replace, as required.
Improper operation of the positive crankcase ventilation (PCV) system	Repair or replace, as required.
Damaged or worn piston and/or rings Oil consumption may or may not cause the engine to misfire.	Inspect the spark plugs for oil deposits. Refer to Spark Plug Inspection in Engine Controls - 3.5L (L66). Inspect the cylinders for a loss of compression. Refer to Engine Compression Test . Perform cylinder leak down and compression testing to determine the cause. Repair or replace, as required.