Why does the car shake a little when starting?
3 Answers
The degree of shaking during car startup has become an important indicator to measure the level of a car. If you notice severe shaking, it indicates an abnormal condition in the vehicle, and you should stop and inspect it promptly to avoid more serious dangers. Below are the reasons for car startup shaking: 1. When there is excessive carbon buildup inside the engine, the gasoline sprayed by the cold start injector will be largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts. This makes starting difficult, and it becomes easier only after the carbon deposits have absorbed enough gasoline to reach saturation. 2. After starting, the gasoline adsorbed on the carbon deposits will be sucked into the cylinder by the engine's vacuum suction force for combustion, enriching the air-fuel mixture. The engine's combustible mixture alternates between lean and rich, causing idle shaking after a cold start. Solution: Clean the fuel system and check if the idle air control valve has carbon buildup; it should be thoroughly cleaned.
I've been driving for over a decade, and most shaking during startup is usually due to issues with the engine's ignition system, such as aging spark plugs or excessive carbon buildup, leading to uneven ignition. Another common cause is loose engine mounts, which can transmit vibrations to the car body. Fuel system problems, like clogged fuel injectors, can also make the car wobble during startup. Minor shaking, if not addressed promptly, can easily develop into engine misfires or more significant failures. It's recommended to perform regular maintenance, replace parts as needed, pay attention to driving sensations, and keep the car running smoothly.
I often experience shaking during startup when driving. Last time, my old car shook violently, and a simple check revealed that the spark plugs were faulty. After replacing them, it immediately ran smoothly. A dirty air filter or using low-quality fuel can also cause shaking. Since then, I've developed the habit of checking the air filter and fuel quality during seasonal changes, addressing issues early to save both hassle and money while extending the car's lifespan. Early-stage shaking is easy to handle, but ignoring it could lead to expensive engine repairs, which is quite troublesome.
