What Causes Severe Engine Vibration in the Morning?

[LukeLee]

Severe engine vibration in the morning can be attributed to the following reasons: Severe Engine Carbon Deposits: The most common cause of car vibration is a dirty throttle body or excessive carbon deposits in the fuel injectors. When there is too much carbon buildup inside the engine, the gasoline sprayed by the cold-start injector is largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts, making it difficult to start the engine. Ignition System Issues: Check the condition of the spark plugs, high-voltage wires, and ignition coils. Poor performance of the ignition system or spark plugs can also lead to such symptoms. Unstable Fuel Pressure: If you have already cleaned the engine carbon deposits, cleaned the throttle body, and replaced the spark plugs but still notice body vibration at idle, it is recommended to check whether the fuel supply pressure and intake pressure sensors are functioning normally.