Why does a Toyota shake when in D gear?

[SanCaleb]

When waiting at a red light with the gear in D and the brake pedal pressed, the car shakes noticeably, but the shaking stops when shifted to N gear. This is not a fault in the car but a normal phenomenon. The details are as follows: 1. The shaking comes from the transmission because the gear is in D, which means the power is connected. The engine's power is transmitted to the transmission, which then sends it to the wheels through the driveshaft. The car is supposed to move forward, but since the brake is pressed and it can't move, the transmission is constantly under tension, causing the shaking. 2. This shaking occurs in every car, but it is more noticeable in some cars and less so in others, sometimes even imperceptible. This is because some cars have better noise and vibration control, effectively isolating the shaking so that it doesn't reach the interior of the car.

[BrookeLee]

A while ago, my Toyota had the same issue—the whole steering wheel would shake when waiting at a red light in D gear. At first, I thought it was a tire problem, but the repair shop found that the engine mount rubber pads had aged and cracked. These things tend to harden and crack after five or six years, reducing their damping effect, causing the engine and chassis to vibrate directly against each other. They also discovered a layer of black sludge buildup in the throttle body, leading to unstable idling. The mechanic said Toyotas are prone to carbon buildup, especially those frequently driven on short trips. He replaced the mount pads, cleaned the throttle body, and also changed the spark plugs. Now, it’s so quiet at red lights it feels like the engine is off. A reminder to everyone: address this early—don’t wait like I did, shaking for half a year before fixing it, as it can easily damage other components.

[LeDamian]

Many car owners often ask me about D-gear vibration issues. In fact, the most common cause is damaged engine mounts. Those rubber pads are designed to absorb engine vibrations. When they age, the rubber hardens or cracks, allowing engine vibrations under D-gear load to transmit directly to the car body. Another common reason is dirty transmission fluid—excessive impurities can affect torque converter stability. Excessive spark plug gaps are also problematic, as insufficient ignition energy leads to poor cylinder performance. A dirty mass airflow sensor is another hidden issue that can cause inaccurate air-fuel mixture calculations by the ECU. I recommend checking these four areas first: lift the vehicle to inspect engine mount gaps—replace if exceeding 1 cm; then check transmission fluid condition and level; next test each cylinder's ignition coils; finally clean the throttle body and airflow sensor. Most vibration issues stem from aging of these fundamental components.

[MacJoseph]

The vibration issue is indeed quite annoying. When I drove my old Camry, I could feel the seat vibrating when holding the brake in D gear. Later at the 4S shop, they diagnosed it as an ignition system problem. The four spark plugs had gone 60,000 kilometers without replacement, and the electrodes were nearly worn out, causing incomplete combustion of the air-fuel mixture. They also found metal debris in the transmission fluid, likely from worn clutch plates. The mechanic explained that the transmission torque converter continuously outputs torque in D gear, and if the fluid is dirty or torque is insufficient, it can cause body resonance. They recommended changing the transmission fluid every 40,000 kilometers and replacing the spark plugs every 50,000 kilometers. Don't wait for problems to arise before servicing—this is not an area to skimp on.