I'm not sure about this but here it goes! Well my prelude has been burning alot of oil lately, yes i know H22's run rich and burn alot of oil, but this is a little abnormal. About every week or so my rear bumper has alot of black carbon build up on it. And whenever I get on the gas, the car seems to puff out black smoke, it does this during the VTEC crossover, but will sometimes do it in higer RPM's. Also I have put about 2 1/2 Quarts of oil in it between an Oil change. So this is my question, is this a cracked valve, and if so does this mean I have to rebuild?