Why does the car make a buzzing sound when releasing the throttle but not when accelerating?
2 Answers
When a car makes abnormal noises upon releasing the throttle but not during acceleration, it is typically due to an issue with the half-shaft. Over time, the half-shaft can suffer from bending, twisting, fractures, or wear and misalignment of the spline teeth due to prolonged torsional fatigue and impact forces. A faulty half-shaft can cause rhythmic shaking in the front of the car when accelerating within a certain speed range, accompanied by a clicking sound. The shaking usually diminishes or disappears when the throttle is released. Correct method for pressing the accelerator: When driving uphill, avoid pressing the accelerator pedal all the way down. In low gear, it is generally advisable to press the pedal halfway. Similarly, when climbing a slope, do not press the accelerator pedal fully. If the engine does not respond with increased RPM even after pressing the accelerator three-quarters of the way, shift to a lower gear and then press the accelerator to accelerate. Before stopping or turning off the engine, always release the accelerator pedal gently and avoid revving the engine abruptly. Key principles: Press lightly and release smoothly, accelerate in a straight line, apply force gently, avoid sudden movements, use the tip of your foot, and avoid jerking. If there are abnormal noises when pressing the accelerator, it is not an engine issue but rather loose nuts on the front drive shaft. Simply tightening them at a repair shop will resolve the problem. If you encounter accelerator pedal issues while driving a new car, do not panic. Follow the advice of professionals: firmly press the brake pedal to bring the car to a complete stop, turn off the engine, and then contact for assistance.
Oh man, I drive quite a lot, and this issue of buzzing noise when releasing the throttle but not when accelerating—in my opinion, it's probably the engine belt or bearing problem. When you press the accelerator to speed up, the engine RPM is high, masking the noise. But when you release the throttle to decelerate, the RPM drops, and those loose components start buzzing, like a tensioner not being tight enough or an aging belt. I’ve seen a similar case last time I was at the repair shop—the owner thought it was a minor issue, but the belt snapped and left them stranded on the road, costing over 800 bucks to fix. You should regularly check if the belt is worn out and not ignore it for convenience. If the car is older, pay even more attention. If you really can’t figure it out, just take it to the repair shop and let the mechanic diagnose it. Safe driving is the top priority—don’t let a small problem turn into a major disaster.
