What Causes the Engine to Make a Buzzing Sound?
2 Answers
Engine making a buzzing sound is due to a malfunctioning temperature sensor or temperature regulator. The specific reasons for the engine buzzing sound are as follows: Malfunctioning temperature sensor or temperature regulator: When the car is in normal idle state, the buzzing sound is caused by the operation of the electronic fan used for radiator cooling. However, this sound is intermittent. If the buzzing sound persists, it indicates a malfunction in the temperature sensor or temperature regulator. The owner should promptly check to avoid abnormalities during driving, which could lead to more severe car failures and economic losses. Excessive gap between piston and cylinder wall: The buzzing sound at low speed or during gear changes is caused by an excessive gap between the piston and cylinder wall. This can occur due to overly tight assembly during installation or abnormal wear. Another reason could be engine knocking, which initially manifests as a buzzing sound. This might be caused by advanced ignition timing or excessive carbon deposits in the cylinder. Sound resonance: The buzzing sound during high-speed operation is due to sound resonance. During high-speed operation, using the wrong engine oil can also cause this phenomenon. Incorrect engine oil may prevent sufficient lubrication inside the engine, leading to a buzzing sound. Alternatively, a malfunctioning water pump, whether clogged or leaking, can also cause the engine to emit a buzzing sound.
I've been driving for over 20 years and have encountered engine humming issues several times. The most common cause is problems with the belt system. For instance, a loose tensioner or a worn-out belt can produce that continuous low-frequency hum, especially noticeable during acceleration. It might sound trivial, but if left unattended, the belt could snap completely, affecting the engine's cooling and charging functions and eventually leading to a breakdown. Another possibility is a faulty water pump or alternator bearing, which can also create a humming noise. Bearing wear occurs due to daily bumps and high temperatures. Additionally, a clogged intake system, such as a dirty air filter restricting airflow, can cause similar sounds. If the humming is particularly noticeable at idle, try opening the hood to locate the source or gently pressing on the belt to see if the noise changes—this can help with initial diagnosis. In short, don't ignore it; getting it checked by a professional is safer because a small hum might hide a major issue that could compromise driving safety.
