Reasons and Solutions for Vibration When Braking in D Gear

[DeEverett]

Reasons and solutions for vibration when braking in D gear are as follows: 1. Continuous and obvious vibration in D gear: The situation improves immediately after shifting to N gear. This may be due to interference between the engine, transmission, exhaust pipe, and the floorboard or body, or aging and cracking of damping rubber, causing the engine's normal vibration to be directly transmitted into the car. The most common cause is insufficient clearance between the lower part of the engine and the floorboard. In neutral gear, there might still be some clearance, but when shifting to D gear, the engine's displacement under load causes direct contact with the floorboard. Other causes include aging or cracking of engine damping rubber, deformation of the exhaust pipe, or aging of exhaust pipe hangers. Typically, such faults can be resolved by prying open certain parts of the engine or exhaust pipe, and the vibration disappears immediately. 2. Intermittent vibration: This may be caused by a dirty throttle valve, excessive carbon deposits in the intake pipe leading to low idle speed, misfiring in the ignition system (bad spark plugs or ignition coils), or poor fuel quality. These issues are related to the engine's operating condition. Shifting to N gear may improve the situation, but occasional engine vibration can still be felt. Based on the vehicle's mileage, check for carbon deposits or spark plug condition, or try changing the fuel and observe. 3. Resonance: This can be caused by improperly installed, loose, or resonating parts in the engine compartment, such as the intake pipe, air filter housing, radiator, headlights, gear shift cable, wiring harness, etc. Loose or improperly installed components inside the dashboard can amplify normal vehicle vibrations through resonance. This can only be resolved by careful inspection and resetting or by slightly increasing the idle speed to avoid the resonance point. Additionally, issues like internal jamming in the compressor, excessive load, or excessive clearance in the cooling fan may also cause noticeable vibration in D gear. Different models or individual vehicles may vary. Generally, cars in D gear will have slightly more vibration than in N gear. If the vibration in D gear is noticeably affecting comfort, it is recommended to have the vehicle inspected at a dealership or repair shop.