The main reasons are: turbocharger inlet and outlet interface due to the connection 

or sealing is not good, leakage noise; If a foreign body enters, it will cause damage 

to the turbine or compressor impeller blades, and the movement of the gas in the 

work will make the supercharger strongly vibrate and produce high-frequency noise; 

The rotor shaft is seriously worn, the floating bearing clearance is too large, the 

turbine blade or bearing is damaged, the turbine rotor accumulates carbon, the axis 

motion track of the rotor shaft changes, the vibration of the rotor shaft is aggravated, 

the dynamic balance is lost, and noise is generated.

The method of exclusion is: check whether the turbocharger air filter is blocked, 

whether there are foreign bodies in the compressor intake pipe or compressor 

housing, diesel engine exhaust system, diesel engine intake or exhaust pipe is 

loose, as appropriate to clean or tighten. If the abnormal sound is obvious metal 

friction sound, should check whether the lubrication of the supercharger is good, 

whether the bearing is loose, whether the turbine blade is deformed, whether 

there is friction between the impeller and the shell, whether there is mud in the 

impeller and the shell, whether the radial and axial clearance is beyond the limit, 

as appropriate; If the turbocharger vibration is strong, it is due to the rotor shaft 

assembly imbalance or floating bearing damage caused by, should decompose 

the turbocharger, check whether there are foreign bodies or parts are damaged, 

according to the situation or change parts.