1999 Subaru Forester 2.5L Oil on Spark plug

HEAVENLYAUDIO

MEMBER
1999 SUBARU FORESTER
4 CYL
AWD
315,000 MILES

The motor is running VERY rough and there is oil on one of the spark plugs. The sound the engine is making is similar to a tensioner pulley that is bad, however the noise almost stops when you disconnect the plug wire that is attached to the Spark Plug that is covered in oil. This happened when I went to start the car after filling with gasoline. It was not acting strange at all before I shut it off, it was when I started the car again. What could cause this?

3 Replies

KHLOW2008

MECHANIC
41,814 POSTS

Seems the engine is misfiring causing the problem. Oil contamination can cause the sparks to go a stray due to short circuiting. It can occur anytime so it is not surprising to have it occur at the next start up.

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Friday, December 10th, 2010 AT 7:19 PM

HEAVENLYAUDIO

MEMBER
2 POSTS

Ok, you are totally off base. There is MAJOR shaking in the motor it mis MAJORLY misfiring. The Spark Plug is TOTALLY covered in oil, not just on start up! Are you saying that this is simply a plug wire or spark plug or coil issue? There is a sound as if the timing pulley beaqring is loose, but that would have nothing to do with the plug being covered. Do you have more advice?

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Tuesday, December 14th, 2010 AT 2:43 PM

KHLOW2008

MECHANIC
41,814 POSTS

If the spark plugs is covered with oil the oil can cause misfiring and also damage the spark plug wires.

The misfiring couls also be due to others problems such as injectors, engine compression etc.

What is seen first should be rectified before proceeding with further diagnostics if it does not solve the problem.

What type f noise are you hearing?

Which timing pulley are you referring to?
Could the noise be due to drive belt related components?

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Tuesday, December 14th, 2010 AT 3:09 PM