What Causes Shaking When Braking in D Gear?
2 Answers
If the shaking when braking in D gear is slight, it is a normal phenomenon. However, if the shaking is severe, it may be caused by damage to the engine mounts. The engine mounts, usually made of rubber, are located where the engine connects to the frame and serve to cushion the engine's vibrations. D gear, also known as the drive gear, engages the corresponding forward gear hydraulic circuit automatically based on throttle opening and vehicle speed signals when the gear selector is in this position. Automatic transmission cars use an automatic transmission to adjust speed, where the transmission's control system automatically selects the appropriate gear based on engine speed and load, replacing the driver's subjective judgment and manual gear shifting.
When your car shakes while in D gear with the brake pressed, I often hear owners complain about this issue. The main reason is unstable engine idling—when the engine speed is too low or unstable at idle, the transmitted force causes the car to vibrate. Specifically, it could be due to old spark plugs. After years of use, the ignition efficiency of spark plugs declines, leading to fluctuating engine power. Another possibility is a clogged mass airflow sensor, located on the intake tract—dirt buildup can disrupt air supply, causing the engine to shake. Additionally, worn engine mounts can also lead to this phenomenon. Mounts act as buffers; when they age, they can no longer absorb vibrations effectively. I recommend checking these areas first—don’t let minor issues escalate, as they can affect driving smoothness and even increase fuel consumption. Regular maintenance, such as replacing spark plugs and cleaning the intake system periodically, can help prevent shaking problems.
