Is Engine Shaking During Startup Normal for a New Car?

[SanClaire]

If the shaking is mild, it is considered normal. However, if the shaking is severe, it is recommended to have it inspected at a relevant repair shop. Below is additional information: Severe Engine Carbon Buildup: The most common cause of car shaking is a dirty throttle body or excessive carbon buildup in the fuel injectors. When there is too much carbon buildup inside the engine, the gasoline sprayed by the cold-start injector can be largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts and 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 experience body shaking during startup, it is advisable to check the fuel supply pressure and the intake pressure sensor. Abnormal fuel pump pressure or incorrect readings and poor performance of the intake pressure sensor can also cause body shaking.