Spark plug wells contained a bit of oil

2003 MERCEDES BENZ C230
87,000 MILES • 1.8L • 4 CYL • 2WD • AUTOMATIC
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ALLANWD
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Two of my spark plug wells contained a bit of oil and two did not. My question is, the oil. Is it normal to be in the spark plug wells? If not why would it be there, and not cause any problems?.
I changed the plugs due to a P0302 code. After the change the code was gone. Assuming that the problem is rectified.
Feb 23, 2019 at 3:52 PM
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JACOBANDNICKOLAS
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Hi and thanks for using 2CarPros.

Most likely, the misfire was caused by the oil leak. It isn't normal to have oil there, but it isn't uncommon. The valve cover on this vehicle has o-rings where each spark plug goes down into the head. The o-rings can start to leak and cause oil to gather in the spark plug well. In the event this is happening, a repair would require removal of the valve cover and replacement of the gaskets and o-rings.

The directions for removal and replacement are in pics one and two.

Let me know if this helps or if you have other questions.

Take care,
Joe
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Feb 23, 2019 at 5:46 PM
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ALLANWD
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Replacement was fairly easy thanks to your pdf' s and photo. The wiring harness was the most uncooperative piece to deal with.
Everything seems to be back to normal.
Thanks again for all your help.
Allan
Feb 27, 2019 at 5:48 PM
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JACOBANDNICKOLAS
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Welcome back, Allan:

I'm glad to hear it helped and you're back in business. Take care and feel free to come back anytime if you have questions.

Take care,
Joe
Feb 27, 2019 at 7:53 PM