What Causes the Buzzing Sound During Engine Idle?

[OAliyah]

This is a normal condition and does not affect usage. Below is relevant information about automobile engine idling: 1. The function of car idling: Idling is an operational state of a vehicle where the engine runs in neutral gear. The rotational speed during engine idling is referred to as idle speed. Idle speed can be adjusted by modifying parameters such as throttle opening. Essentially, idling means the engine is "producing power without performing work." When the accelerator pedal is fully released while the engine is running, the engine enters idle state. 2. Causes of unstable idling: The direct cause involves mechanical components becoming dirty, worn, or improperly installed, leading to variations in cylinder performance. This results in imbalance among cylinders, causing unstable engine idling. The indirect cause stems from abnormalities in the engine's electronic control system, which leads to poor combustion of the air-fuel mixture, making it difficult to balance cylinder performance and resulting in unstable engine idling.