Why is there abnormal noise when releasing the accelerator but not when pressing it?
2 Answers
The reasons for abnormal noise when releasing the accelerator but not when pressing it include the car's half-shaft being prone to bending, twisting, breaking, or wear and skew of spline teeth under long-term torsional fatigue and impact forces. Methods to address abnormal noise when releasing the accelerator but not when pressing it: If you encounter accelerator pedal issues while driving a new car, do not panic. Follow professional advice by fully depressing the brake pedal to bring the car to a complete stop, then turn off the engine and contact for assistance. Correct method for pressing the accelerator: When driving uphill, do not press the accelerator pedal all the way down. When using a low gear, it is generally advisable to press the accelerator halfway. Similarly, when climbing a slope, do not press the accelerator pedal to the floor. If the engine does not respond with increased speed when the accelerator pedal is pressed three-quarters of the way while driving, shift to a lower gear and then press the accelerator to accelerate. Before stopping or turning off the engine, first release the accelerator pedal and avoid suddenly revving the engine in neutral. Key principles: Press gently and release slowly, accelerate in a straight line, apply force softly, avoid abrupt movements, use the tip of your foot, and avoid sudden jerks.
I've always thought that abnormal noises when releasing the throttle are quite common, usually related to exhaust system issues, such as leaks at the exhaust pipe joints or internal cracks in the muffler. When the throttle is released, the engine speed drops, and changes in airflow can cause gaps to produce squeaking or buzzing sounds. However, when the throttle is pressed, the increased load may make the noise disappear. Additionally, worn suspension components might also contribute—loose ball joints or connecting rods can rattle when decelerating. I recommend first checking under the car for loose exhaust pipe screws by shaking them by hand. If that doesn’t help, it’s best to consult a professional promptly, as small issues can escalate if ignored. For daily driving, remember to maintain the exhaust system regularly, as accumulated mud under the car can also cause problems. Safety comes first—abnormal noises can be annoying and may indicate potential hazards, especially when decelerating at high speeds, which can be distracting. In short, don’t ignore them; address the issue early to avoid bigger expenses later.
