Shaft rotates
Deformed, twisted blade (soft foreign object)
Visually check the condition of the turbine and compressor wheels (see pictures). If the rotor wheels are out of order, replace the turbocharger.
Replace the piping coming from the damaged wheel.
Blade breakage (ingress of a solid foreign object)
Clearances: 1 - axial clearance. 2 - radial clearance
Rotor wheels
Feel the axial clearance of the rotor wheels (see illustration). The normal axial clearance is about 2 mm.
If the axial clearance of the turbocharger rotor is excessive, replace the turbocharger.
In the event of a rotor failure:
- change engine oil and oil filter;
- clean the air-to-air cooler and air lines.
Attention! Cleaning the air circuit and changing the engine oil and oil filter is essential. Otherwise, failure of the new turbocharger and engine may occur.
If the axial clearance of the turbocharger rotor does not exceed the norm, the turbocharger is in good condition.
Turbocharger Rotor Clearances
The clearance in the turbocharger rotor bearings is about 25 microns when measured between the turbocharger shaft and the inner surface of the bearings and 75 microns between the outer surface of the bearings and the support.
Attention! In case of destruction of the compressor bearings, particles of steel and bronze will enter the engine oil sump through the oil drain pipe. These particles can then enter the engine lubrication system through the oil pump and cause complete contamination. This will cause accelerated wear of the crankshaft main and connecting rod bearings, camshaft bearings, etc.
In the event of a compressor impeller failure, fragments of the compressor blades can get into the air-to-air cooler and into the air ducts. The fragments of the turbine wheel will immediately be in the catalytic converter.