Ford Repair: Engine damage, positive crankcase ventilation, piston rings

Question
Steve,
I recently changed the spark plugs on my 1998 explorer 4.0, and there was a little bit of oil on one of the plugs. The car also idles a little rough when it first starts and sometimes feels like its struggleing up hills. These problems seem to only occur in the first few minutes of driving. If I give it a bit more gas on the way up a hill, the problem seems to go away. The car has about 100k miles on it. What do you think? Do I have engine damage, or do you think maybe a fuel service will solve the problems?

Answer
Andrew-

  I'd start by replacing your PCV (positive crankcase ventilation) valve.  It's a cheap fix and, if your PCV valve is clogged, your engine can suck oil up past the piston rings among other places.  If the problem remains after the PCV valve swap I'd have a shop check it out.  It could be bad piston rings or a number of other issues.  The PCV valve would just be the easy way out (which is often the best way).  Hope this helps.

Steve