What are the reasons for engine shaking at idle?

[LeMadeline]

Engine shaking at idle is mainly caused by: 1. Unstable oil pressure. If the fuel pump's supply pressure is abnormal or the intake pressure sensor values are incorrect or malfunctioning, it can cause body shaking. Solution: Check oil pressure and replace components if necessary. 2. Severe engine carbon buildup. When there is excessive 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, making it difficult to start and causing the car to shake. Solution: Clean the fuel system and check if the idle control valve has carbon buildup that needs cleaning. 3. Ignition system issues. Poor performance of the ignition system or bad spark plug firing can also cause car shaking. Solution: Check if the spark plugs have excessive carbon buildup and replace them if necessary.