Is overbearing idle jitter a common problem?

Mechanical failure of engine leads to lax valve closing, different cylinder pressures, dirty or damaged throttle valve of air supply system, too low or fluctuating pressure of oil supply system, and serious carbon deposition of injector, which are common.

If you can obviously feel the vibration of the car when you are sitting in the car, feel your hand holding the steering wheel shaking, the pointer of the tachometer jumping up and down, or open the hood of the engine, you can obviously see the engine jitter, indicating that the engine idling jitter is too large.