mercy

I was at full stop behind the traffic light. When the light turned green, I slowley accelerate (RMP betwwen 1000 to 2000 rmp) the speed reached the 25 to 30 MPH. Suddenly, I felt the clunking noise under the car and after that the gas pedal start to vibrate. I still feel the vibration but it is very minor. I have been trying to duplicate the clunking problem and I can not get this to repeat even on the same road but the gas pedal vibration gets worse on the same road.

Has anyone experienced similar issue?