Just immerse the spark plug in a recipient with solvent, kerosene or thinner, and use a hair dryer to get the spark plug dried again.
you can see if its leaking if you have the spark plug in tight and then fill up the spark plug tube with gas and see if it leaks out if it doesn't its still leaking from the top one
if the oil is at the spark plug base the valve cover gasket is leaking. if the spark plug electrode is covered with oil the engine needs rings
My car started over heating. the gauge went up over where its supposed to be. we flushed the radiator out. No leaks from anywere, no cloudy stuff in my oil, not smoke from the engine or tail pipe. then i pulled the spark plug out near the oil cap and there is oil in there...
No there should not be any oil where you plug your spark plugs into
valve gasket leaks normally do not cause this. But if you have an enclosed 4 cylinder spark plug set, the oil can fill the spark plug holes basically drowning the spark plugs with oil. A good example is a dodge neon and 2000 kia sportage. Since you did not specify engine, make or model that is about the best answer to give yopu.
You have an oil leak
Oil deposits on the spark plug is caused by poor oil control. Oil is leaking past worn valve guides or piston rings into the cumbustion camber.
It will not hurt the engine what so ever, But it will make it smoke and might fowl out a spark plug.
if one plug has signs of oil leaks its probably piston rings. only air and fuel should mix in the part of the chamber the plug ignites. so make sure you don't just have too much fuel entering the chamber
If you mean on the exterior of the spark plug then the valve cover gasket is leaking. If it is on the electrode of the plug you are burning oil.
Screw out spark plug then screw in non fouler then screw in spark plug in non fouler.
Oil on the outside of the spark plug is normally a sign of a leaking valve cover gasket. Oil on the spark plug electrode, (plug must be removed to see this oil), is normally a sign of a broken or worn piston ring. A compression test will verify if a ring is worn or broken.