RPM Issues and Vibration under stress
11-01-2010, 05:02 PM
#1
RPM Issues and Vibration under stress A buddy of mine is having some issues with his A4 2000 Trans Am.
The first is that when he cruises (even on flat ground) his car will randomly rev 500-700 RPMs and then drop back down to the RPMs he should be running for whatever speed he is cruising at. This, coupled with a raspy type exhaust leak sound makes me think he has an exhaust leak somewhere around his header collecting pipe that is causing a loss in backpressure and resulting in both the sound and uneven RPM at cruise. What do you guys think?
The other issue is that his car bumps/vibrates? when under more than normal torque. Normal torque being accelerating like you got no where to go on a Sunday afternoon. If he gets on it, even slightly, you can feel a "bumping" through the floorboard and the seats. It's not extremely noticeable, but it's there. My best guess is slipping gears. That the teeth on his gears are pretty worn and that under normal stress they can still bite into each other, but when under a little heavier torque they start to slip??
Any advice is appreciated.
The first is that when he cruises (even on flat ground) his car will randomly rev 500-700 RPMs and then drop back down to the RPMs he should be running for whatever speed he is cruising at. This, coupled with a raspy type exhaust leak sound makes me think he has an exhaust leak somewhere around his header collecting pipe that is causing a loss in backpressure and resulting in both the sound and uneven RPM at cruise. What do you guys think?
The other issue is that his car bumps/vibrates? when under more than normal torque. Normal torque being accelerating like you got no where to go on a Sunday afternoon. If he gets on it, even slightly, you can feel a "bumping" through the floorboard and the seats. It's not extremely noticeable, but it's there. My best guess is slipping gears. That the teeth on his gears are pretty worn and that under normal stress they can still bite into each other, but when under a little heavier torque they start to slip??
Any advice is appreciated.
