What causes the buzzing sound in Audi A3 at 2000 RPM?

[ArabellaMarie]

Audi A3 buzzing sound at 2000 RPM is mainly caused by increased carbon deposits in the throttle body. The following details the reasons and solutions: Increased carbon deposits in the throttle body: The throttle body is a controllable valve that regulates air intake into the engine, available in two types: traditional cable-operated and electronic throttle bodies. After entering the intake manifold, the air mixes with gasoline to form a combustible mixture for combustion. Connected to the air filter at the top and the engine block at the bottom, it is often referred to as the throat of the car engine. Increased carbon deposits in the throttle body absorb some gasoline when the engine is cold. When the engine warms up, this gasoline evaporates, causing an overly rich mixture at idle speed, which leads to low-speed vibrations. Corresponding solution: Release the gases. Engine oil will volatilize when heated during use. The longer the usage time and the higher the temperature, the stronger the volatilization. Additionally, some compressed gas from the cylinders will inevitably squeeze into the crankcase through the piston ring gaps. Therefore, there must be a channel to release these gases; otherwise, positive pressure will form in the oil pan.