What Causes Slight Shaking During Car Ignition?
2 Answers
Engine shaking during car ignition may be attributed to the following two reasons: 1. After driving for a certain distance, a dirty throttle can cause the throttle to not close properly or the idle speed stepping motor to get stuck, both of which can result in excessively high engine idle speed. Additionally, carbon deposits accumulated during engine operation can also cause vehicle shaking, especially when starting the car. The engine may shake more noticeably than usual, and sometimes it may even fail to start on the first attempt. 2. Car shaking can sometimes be related to aging engine mounts. Engine mounts are essentially the shock absorption system of the engine, responsible for absorbing minor vibrations during operation. If the engine mounts are faulty, these vibrations can be transmitted to the steering wheel and the interior of the car, causing shaking during idle.
I feel quite uncomfortable with the shaking when starting the car, as if the body is unstable. Common causes include worn spark plugs, which may cause this if they haven't been replaced for two or three years, leading to inconsistent ignition. If the ignition coil is aging, a cylinder may not work properly, also causing shaking. The fuel system should not be overlooked either—carbon buildup in the fuel injectors can block them, leading to uneven fuel supply, or a dirty air filter can affect the air-fuel mixture. I've experienced it myself—it started with slight shaking, but if not repaired in time, the engine vibration worsens, fuel consumption increases, and long drives become more exhausting. Regular maintenance, such as changing the oil periodically and using high-quality fuel, can prevent most issues. If the shaking happens frequently, it's advisable to visit a repair shop to check the ignition system and intake pipes with tools—don’t wait until the engine light comes on.
