What is the reason why the pressure reducing valve of turbocharger makes noise?

The turbocharger pressure relief valve sounds or the pressure relief valve works normally. Turbocharging process: when the throttle of the turbine starts to work, a large amount of air is compressed and pushed into the engine combustion chamber through the throttle, but when the driver releases the throttle pedal, the throttle is closed. However, the blades of the turbine will not stop working immediately. At this time, there is still residual compressed air in the intake pipe between the turbine and the throttle. If the air is not exhausted in time, the strong pressure will damage the throttle and turbine blades. Introduction of exhaust valve: The exhaust valve is an engine intake supercharger. Air is compressed by the supercharger before entering the engine cylinder, which increases the density of air and makes more air fill the cylinder, thus increasing the power of the engine. The engine equipped with supercharger can not only output more takeoff power, but also improve the altitude characteristics of the engine.