Hi, I have got a Honda Civic, year 95', I refill the car's antifreze all the time because it is empty. Is it possible for the antifreeze to mix with the engine oil into the engine. If so is it a big problem? Should it be fixed A.S.A.P.? The engine is wet (oily) kind of brown/green ish. Does the engine need new gaskets? If I have to repair my car because of this, I should probably pay like $600 and that's a lot!