I have a black oil on air filter when I changed it??
It took a while and I think you meant to type "I have black oil on the air filter when I changed it". -- That's sort of normal. Engine vapors are sent to the intake to be burnt as part of the emissions system.
Ditto. Tenspeed is right. The PCV draws clean air from that canister
There should be a filter in line to prevent that much oil from backing up. What you don't say is how long it has been since the filter was changed. If it has been a LOT of miles, then sure, it could be normal. If it is only a fairly short while, like under 10,000 miles, then there is likely something wrong, and my first guess would be that you have engine blow by to a very significant degree.
Looking for a Used Explorer Sport Trac in your area?
CarGurus has 2,080 nationwide Explorer Sport Trac listings starting at $2,995.
Search Ford Explorer Sport Trac Questions
Ford Explorer Sport Trac Experts