Base Engine Misfire with Excessive Oil Consumption

WARNING: This page is about a different car, the 2005 GMC Yukon XL, 2005 Chevrolet Suburban, and 2005 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Cause	Correction
Leaking intake gaskets	Repair or replace the intake manifold bolts and/or gaskets as required.
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 - 8.1L. Inspect the cylinders for loss of compression. Refer to Engine Compression Test . Repair or replace as required.
Worn piston 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 - 8.1L. Inspect the cylinders for a loss of compression. Refer to Engine Compression Test . Perform cylinder leak down and compression testing to determine the cause. Refer to Cylinder Leakage Test . Repair or replace as required.