What Causes the Buzzing Sound and Resonance Sensation During Car Idling?
3 Answers
The reasons for a car producing a buzzing sound and resonance sensation during idling are: 1. Tensioner pulley wear: Due to prolonged pressure and high-speed rotation, the bearings in the tensioner pulley can easily wear out, causing noise and resonance; 2. Exhaust pipe deformation: A deformed exhaust pipe increases exhaust resistance, leading to a buzzing sound and resonance sensation; 3. Wheel hub bearing wear: Wheel hub bearings are installed in the suspension's "knuckle" and constantly bear the vehicle's weight and impact during daily driving, making the bearing balls inside the wheel hub bearings prone to wear, resulting in a buzzing sound and resonance sensation. Idling is an operational condition of a car, where the engine runs in neutral gear. The engine speed during idling is called the idle speed, which can be adjusted by modifying the throttle opening size, among other methods.
Idle buzzing with resonance feeling is quite common, as I've driven many cars and noticed this issue frequently. It's mostly caused by excessive carbon buildup in the engine, leading to uneven combustion of the air-fuel mixture and unstable operation, resulting in buzzing sounds accompanied by vibrations. Additionally, if there's a leak in the exhaust system, such as a small hole in the exhaust pipe, high-speed gas flow can create resonant noise. Aging engine mounts are another culprit—the rubber pads harden over time, losing their vibration-absorbing ability, allowing engine vibrations to transfer to the car body, making them more noticeable. I recommend first trying to clean the throttle body and fuel injectors to reduce carbon deposits. If that doesn't help, then inspect the exhaust pipe connections and mounts. For prolonged idle periods, regular engine maintenance is crucial to effectively prevent this annoying phenomenon.
My old car used to have a buzzing sound at idle, with a noticeable resonance, which was quite uncomfortable. After inspection, it turned out to be an exhaust leak, amplifying the sound into a buzz. Or it could be a loose drive belt slipping on the pulley, especially louder when the AC is on. Aging belts and damaged exhaust systems easily cause resonance, making the whole car vibrate. It's best to have a repair shop check the connections and tension. Small issues left unattended can lead to bigger problems, like increased fuel consumption. If you hear this sound while driving, slow down and pull over safely. Remember to regularly inspect the exhaust system and replace old belts to avoid such troubles.
