What Causes Engine Shaking During Ignition in Small Cars

[McPeter]

Engine shaking during ignition in cars may be attributed to the following two reasons: 1. Dirty throttle body or excessive carbon buildup in fuel injectors can cause shaking. After a certain mileage, a dirty throttle body can lead to incomplete closure or idle stepper motor sticking, both of which can result in excessively high engine idle speed. Additionally, carbon deposits generated during engine operation can also cause vehicle shaking, especially during startup when the engine shakes more noticeably than usual, sometimes even failing to start on the first attempt. When experiencing vehicle shaking, the first step is to inspect the throttle body and fuel injectors. If excessive dirt or carbon buildup is found, immediate cleaning is recommended. 2. Worn engine mounts can also cause shaking. Car shaking may sometimes be related to aging engine mounts. Engine mounts essentially serve as the engine's vibration damping system, absorbing minor vibrations during operation. If the engine mounts malfunction, these vibrations can transfer to the steering wheel and cabin, causing noticeable shaking during idle.