Why does the resonance disappear when accelerating at idle?
2 Answers
The reasons why engine vibration at idle disappears when accelerating are: 1. Changes in fuel injection quantity cause the engine speed to fluctuate; 2. Faulty fuel pump pressure regulator or sensor leads to incorrect fuel injection correction signals; 3. Cracked vacuum booster pipe; 4. Carbon buildup or dirt on the throttle body, or incorrect position of the throttle position sensor. Additional information: An engine (Engine) is a machine capable of converting other forms of energy into mechanical energy, including internal combustion engines (reciprocating piston engines), external combustion engines (Stirling engines, steam engines, etc.), jet engines, electric motors, etc. The term engine can refer to either the power generation device or the entire machine including the power unit.
Ah, my old buddy who's been driving for over twenty years often encounters this situation where the car hums at idle but the noise disappears when accelerating. It's mostly due to aging or loose engine mounts. At low idle speeds, the vibrations happen to match the defects in the mounts, causing resonance. When you step on the gas, the RPM increases and the frequency changes, so the resonance disappears. Additionally, if the exhaust system's hangers are damaged, it can also cause this. The exhaust pipe shakes severely at idle but stabilizes with high-speed airflow, reducing vibrations. It's recommended to visit a repair shop as soon as possible to avoid major issues like mount breakage or engine displacement. Usually, after parking, take some time to listen to the engine compartment sounds to detect signs of aging early.
