Take This Quiz To Find Out If You’re A Car Engine Expert!

Why would your spark plugs be covered in oil when changing them?

Retry Correct Incorrect If there is oil on the spark plugs, it’s usually because the piston rings or valves are leaking. This can cause the engine to end up misfiring or have a weak spark.

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Jason Smith/Getty Images for NASCAR

Jason Smith/Getty Images for NASCAR

Why would your spark plugs be covered in oil when changing them?

• The camshaft is leaking
• There’s a hole in the engine
• The crankshaft is leaking
• The valves or piston rings are leaking