Is It Normal for a Car to Shake Violently at the Moment of Ignition?
1 Answers
The reason for a slight shake at the moment of ignition is the cold start of the vehicle, which can sometimes cause minor vibrations. As long as the shaking is not too severe and does not last long, it is considered normal. However, persistent shaking is abnormal. Here are the general reasons for car ignition shaking: 1. Incomplete combustion of gasoline in the engine, resulting in insufficient power, or a stuck or clogged fuel injector. Most engine shaking is caused by insufficient fuel supply due to clogged or stuck fuel injectors, leading to power loss. 2. Aging spark plugs due to prolonged use can cause the electrode gap to widen, leading to insufficient ignition energy and poor gasoline atomization. Additionally, many modern cars have three- or four-cylinder engines, each with a spark plug. These spark plugs can also develop widened gaps, causing power differences between cylinders and resulting in vehicle shaking. 3. Excessive carbon buildup in the engine's intake manifold and valves, which may be caused by a dirty throttle body or too much carbon buildup in the fuel injectors and intake passages. During a cold start, carbon deposits can absorb some fuel, preventing it from fully entering the combustion chamber. This leads to unstable idling, and during a cold start, carbon deposits may absorb some gasoline, causing the air-fuel mixture in the engine cylinders to become too lean, resulting in engine shaking and difficulty starting.
