What causes severe shaking when pressing the brake in D gear?
3 Answers
The reasons for severe shaking when pressing the brake in D gear: damage to the engine mounts, insufficient engine power due to poor fuel supply. The connection points between the engine and the frame are equipped with engine mounts, which are usually made of rubber. These mounts help absorb engine vibrations. D gear, also known as the drive gear, engages the forward gears automatically based on throttle position and vehicle speed signals when the gear selector is in this position. P stands for Park, used when the vehicle is stationary, locking the wheels mechanically to prevent rolling. R is Reverse, used for backing up. N is Neutral, used for temporary stops.
The car I drove before also often had this issue, especially when stopped at traffic lights. With the gear in D and the brake pressed, the whole car would shake violently. Most of the time, it's related to unstable engine idle speed because the engine wants to move forward while the brake is holding it back, creating an imbalance that causes shaking. For example, aging spark plugs, a dirty air filter clogging the intake, or excessive carbon buildup in the fuel injectors affecting fuel delivery can all lead to unstable idle speed. Loose or damaged engine mounts should not be overlooked either—they absorb vibrations, and if they fail, engine vibrations will directly transfer into the car. Another possible cause is issues with the braking system, such as worn brake pads or sticky calipers preventing the brakes from fully releasing. Combined with the transmission's power output, this makes shaking more likely. If you encounter this situation, don't push through it. First, park the car safely, turn on the hazard lights, and have an experienced mechanic use a diagnostic tool to check for trouble codes. Once the issue is identified, get it fixed promptly—don't risk bigger problems by trying to save money.
Severe shaking when the car is in D gear and the brake is pressed is mostly due to an issue with the idle control system, causing instability when the engine maintains low RPM. First, consider the ignition components. If the spark plugs have been used for a long time without replacement, their ignition capability decreases, affecting combustion efficiency and leading to fluctuating RPM. Also, check the intake system. A clogged air filter or a dirty throttle body can restrict airflow and disrupt idle stability. Additionally, don’t overlook the engine mounts. Over time, the rubber material can age and crack, losing its damping effect, which amplifies the engine's minor vibrations throughout the car. The braking system shouldn’t be ruled out either. If the brake discs are warped or the brake calipers are sticking, they may continuously clamp the discs, causing a tug-of-war between the engine’s forward thrust and the braking force. A simple solution is to use an OBD diagnostic tool to read fault codes or listen for abnormal engine sounds. Pay attention while driving, and if the shaking frequency increases, investigate promptly to prevent minor issues from escalating.
