Today I changed the spark plugs on my 2006 Endeavor. To my surprise, 4 of the 6 plugs had oil on the plugs, electrode and also on the ceramic. I will admit, I have 90k on the engine and I never bothered to replace the plugs until now. The engine was running fine prior to replacing the plugs. No smoke in the exhaust or anything like that. When I started the engine I noticed a bit of smoke for a minute or so, but then it went away. I am thinking that maybe the plugs were so old that they possibly were failing and the smoke was the engine burning off all the excess oil in the cylinders? I plan to pull a couple of the plugs next week to see how they look, but in the meantime, has anyone experienced anything like this before? By the way, if anyone is looking to replace their plugs and not sure how to remove the intake, someone posted a PDF on this site pointing out all the bolts and wiring that needs to be removed including photos. It is extremely helpful. Thanks in advance.