What are the causes of idle shaking in D gear for a new car?

[LaKinsley]

New car idle shaking in D gear can be caused by the following reasons: Excessive carbon deposits: If there is severe carbon buildup inside the engine cylinders, it can lead to clogged spark plugs and valves, directly causing the car to shake during idle. If the vehicle's acceleration performance has significantly declined and the shaking persists for a long time, consider cleaning the engine cylinders. Fuel supply system malfunction: Unstable oil pressure in the fuel supply system can easily cause fluctuations in the concentration of the air-fuel mixture, not only resulting in shaking but also causing unstable idle. First, consider replacing the fuel filter, as prolonged use can lead to clogging. Then, check the oil pressure bypassing the fuel filter. If abnormal, it might indicate a fuel pump issue. Engine mount aging: If the engine shaking becomes increasingly severe but the power output does not weaken accordingly, it could be due to a problem with the engine mounts. Misfire: The most common cause of engine shaking, if not the only one, lies in the engine ignition coils or spark plugs. If the ignition coils malfunction or the spark plugs fail to fire for some reason, the car will exhibit shaking.