I have a vibration. Its all engine. The whole car shakes at idle. I thought it was a plug or plug wire, replaced both plus new cap and rotor, no help. If i rev the engine up it seems like the car wants to move with the clutch depressed. Not sure if it is part of it. Car has 252,000 miles on it. Never had a problem like this. Any ideas? Doesn't matter if car is moving or not.