What Causes the Buzzing Noise in the Engine?

[OLukas]

Reasons for engine buzzing noise: 1. After starting the car, the engine makes a "buzzing" noise, which is the sound of the valves. This is especially noticeable when starting a cold engine, as the oil pressure hasn't built up yet and the valves aren't properly lubricated. It usually goes away after a short while. 2. If the car has been parked for a long time, this situation may occur. 3. The buzzing noise at low speeds is usually caused by excessive clearance between the piston and the cylinder wall, which can occur due to abnormal wear during installation if the components are too tight. 4. A buzzing noise can also be an early sign of engine knocking, which may be caused by advanced ignition timing or excessive carbon buildup in the cylinder. 5. This phenomenon can also occur during high-speed operation if the engine oil is not properly selected.