[dcleckler]

As the engine in my 2002 tracker reaches enough rpm's to shift into the next gear (automatic tranny), it makes a buzz/vibration (like an exhaust rattle) sound, but disappears instantly when the tranny actually shifts, then comes back as it nears the next shift. I can also make it do this as I make the rpm's go up, even without shifts. So, I know its not the tranny. I sounds like exhaust or exhaust shield or something. Its coming from underneat the drivers side and at first I thought it was just a spedometer cable being rusty but I think I have that problem also. I can hear the other noise if I listen outside the car with the window rolled down. You can hear it coming from underneath the car. Sometimes it doesn't do it as much. It seems to do it only at a specific rpm and then the rattle stops. You don't hear it at all as the engine levels out on the road.

Any advice?