What Causes Severe Engine Shaking in Reverse Gear While Running Normally in Forward Gear?

[StSpencer]

The causes of severe engine shaking in reverse gear while running normally in forward gear are aging engine mounts and severe carbon buildup in the engine. Below are the relevant explanations: Aging Engine Mounts: They need to be replaced promptly. Engine mounts, made of rubber, are located where the engine and transmission connect to the vehicle body. Rubber components degrade over time with use. Severe Carbon Buildup in the Engine: The most common cause of car shaking is a dirty throttle body or excessive carbon deposits in the fuel injectors. When there's 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. This makes the engine hard to start. Under these conditions, the engine only starts easily once the carbon deposits have absorbed enough gasoline to become saturated. After starting, the gasoline adsorbed on the carbon deposits is drawn into the combustion chamber by the engine's vacuum suction, enriching the air-fuel mixture again. This fluctuation between lean and rich air-fuel mixtures causes the engine to idle roughly after a cold start.