How could you be getting oil in the air filter on an 88 Lincoln town car found a small oil leak but cant tell where it is coming from changed valve cover gaskets any more suggestions?

A small amount of oil on the air filter is normal. It comes from the pcv valve up to the air cleaner box. This is to prevent the oil from being blown out into the atmosphere without being buned first. (It's an emmissions thing) If you arent using tons of oil and the car is running ok dont worry with it. (I assume your town car has a 5.0 liter engine) Please let me know if you have any more questions. Justin justin25taylor@Yahoo.com