Base Engine Misfire with Excessive Oil Consumption

WARNING: This page is about a different car, the 2004 GMC Sierra and 2004 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Cause	Correction
Worn or damaged valve	Inspect the valves. Inspect the valve guides. Repair or replace damaged components as required.
Worn, damaged or improperly installed piston rings Piston rings must be installed with the mark, or dimple, on the top of the piston ring, facing up.	Inspect the spark plugs. Refer to Spark Plug Inspection in Engine Controls. Verify engine compression. Refer to Engine Compression Test . Inspect the cylinder bores. Inspect the pistons. Inspect the piston pins. Inspect the connecting rods. Repair or replace damaged components as required.