Is there any thing wrong? will that oil soaked spark plug produce spark? Will I lose MPG?
Thank you for help.
Oil fouling means that that cylinder is sucking oil. You cannot tell just from the presence of oil fouling that the problem is a leaking gasket: there could be several other causes, such as worn or broken rings, a scored cylinder, a worn valve guide, or a broken valve stem seal.
If the mechanic has done other tests that more clearly indicate a leaking gasket, he would be right about it needing replacement. It may be easier to live with other problems if you're not intent on keeping the car a long time.
Do you mean the electrodes on the plug had oil on them, or the outside of the plug? If it's the outside, and your valve cover gasket is dumping oil on the plug, then eventually the oil can cause the ignition voltage to leak and cause the engine to misfire.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.