First off, yes, my car is an old one. A 1990 Honda Civic DX Sedan. However, I have taken pretty good care of it for the most part and this has never gone away (I guess car inspections don't suffice). Whenever I am in the park position, my car will make its regular groaning sound as any other car does, but then it will sometimes begin to make a repetitive revving sound as if I am pressing the gas pedal while in neutral. The pattern is not perfect as it will sometimes stop and then return to the revving rhythm, but it sounds as if my car is exhausted (no pun intended) and trying to catch its breath or about to fail completely. Anybody have a clue or had this happen and what should/can I do to fix it? Is it even worth fixing? People give me odd looks when I'm in line for fast-food as I appear to want to race or some crap, haha. Help!