Why does an automatic transmission car shake when accelerating?
2 Answers
Automatic transmission cars may shake during acceleration due to the following reasons: 1. Component failure: The fuel system of a car is relatively large and consists of many parts. Any abnormality or failure in one of these components can cause the engine to shake during acceleration. Examples include excessive carbon buildup in the throttle, faulty fuel injectors, malfunctioning fuel pumps, clogged fuel filters, etc. 2. Degraded spark plug performance: In the engine ignition system, ignition high-voltage wires rarely cause issues. The main problems usually lie with the ignition coils and spark plugs, as they are wearable parts. When spark plug performance degrades or inferior quality spark plugs are used, it can lead to weak acceleration and shaking during acceleration.
My car previously had an acceleration shudder issue. When stepping on the gas pedal, I could feel the entire body shaking, especially noticeable when overtaking on highways. Initially, I thought it might be unbalanced tires, but after inspection, it turned out to be misfiring caused by aged spark plugs. The shudder disappeared after replacement. It could also be due to excessive carbon buildup on ignition coils or throttle bodies affecting the air-fuel mixture. Additionally, if the fuel line is clogged or the fuel pump has insufficient pressure, inadequate fuel supply can make the engine run unsteadily. I've also heard that when the torque converter in automatic transmissions wears out, it can transmit vibrations during acceleration. This problem shouldn't be taken lightly—if the shaking worsens and leads to loss of control, it could be dangerous. I recommend getting a comprehensive diagnosis at a repair shop as soon as possible. Using high-quality fuel during regular maintenance can help reduce carbon buildup.
