Oil found in spark plug well - 3.7 V6
2007 Grand Cherokee with the 3.7 V6 engine
Oil found in the passenger side center spark plug well.
Engine was missing under load which led to the spark plug change.
Hello, while helping my daughter change the spark plugs on her 3.7 V6 engine, we found a lot of oil in the spark plug well.
I reviewed a DIY spark plug change YouTube video so we had a good reference about how to do the work and the tools necessary. I started on the drivers side and completed it without any problems. Got to the passenger center plug and found the oil when I removed the coil and plug.
The first indication was the expanded rubber seal on the coil that sits at the top of the well. When the plug was removed, whatever oil was in the well traveled down into the cylinder. The old plug had oil above the metal and on the ceramic insulator. It probably was the cause of the misfire under load.
We called a local mechanic friend and the dealer service department. No one had any definite ideas about the source of the oil. The business end of the old plug did not show any burnt oil.
It looks like the oil came from above but I could not find any source. The dealer mentioned the valve cover gasket and said something about oil passages in the intake. There was some sort of vent hose directly above the center well. I moved that outboard to the dip stick tube.
We cleaned it up and put it back together with the new plug. The engine smoked for a minute as the oil in the cylinder burnt off.
My daughter has a extended warranty for the life of the loan and she is going to take it to the dealer so they can check it.
Has this happened before? Is it a common situation with the V6? I did search the engine and WK forum but didn't find anything mentioned.
Thanks in advance,
Honeoye, New York