ok, driving my sho and all of a sudden no power. the noise is from the rear head on the middle spark plug well. the boot flew off and oil came shooting out. probably from the well being full. but the noise sounded loud like, a knocking kinda it was a vacuum leak. put the boot on on it got a little quiter but still noticable. theres pressure so it wont stay on . could a bad o ring cause this or do i have a loose plug? the engine only has 100k