I know a bit about cars however I'm in need of assistance. I have a 1998 Saturn SW1- when accelerating and the rpms reach 2 (always 2) the Pass side of car makes a vibrating sound. I popped the hood and reved the engine but could not hear the noise outside the car-only inside. if rpms reach 3 the noise stops and if I keep them below 2 there is no noise. I was originally thinking busted motor mount but just not sure. the only thing I've needed to do to the car was replace the idle air control valve, other than that the car seems to run fine. any ideas would be great- thanks