Worn valves, valve guides, and/or valve stem oil seals

• Inspect the spark plugs for oil deposits.
• 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.
• 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.