We've been leaking oil for awhile - car needs more oil about every month and a half, to two months. Not really sure where it's leaking from - somewhere in the front of the car. It's NOT the plug; oil change guy ruled that out the other day. He said "somewhere towards the top; not the plug."

At our last 30,000 mile tune up (which was about 30,000 miles ago) the mechanic said we had a crack in our head gasket, but didn't need to be replaced right now. So I'm guessing that could be the cause of our oil leak? Haven't had any problems with the car overheating or anything...

When do they determine they need replaced? If it does need replaced, how much does that run? Also, what problems/symptoms can a cracked head gasket cause?

We have a 2000 Saturn with 120,000 miles on, if that matters at all (I don't know a lot about cars).

Just for the record, we've never noticed white smoke, or coolant mixed w/ our oil (or vice versa) or had anyone say anything about it to us at our regular oil changes. Never had any problems with the car over heating or anything either.

I only have the word of the mechanic (who is also a friend) who told me of the cracked head gasket a few years ago, and that at the time didn't need replaced yet.

Want to make sure we can get our car to last at least another 2 years if possible. :)