my 90 civic dx is leaking oil. just changed it out for new stuff, with a new filter and i know i put everything on nice and tight. it was leaking when the original owner had it too. where are some common areas that these cars form leaks? it shouldnt be anywhere a beaten car would have it as my car has 103,000 original miles, and was babied by the last owners. any suggestions on where to check? (the oil is the crank-case type [brown]) thanks, nick.