Yanmar 4LHA-HTP Operation Manual page 502

Chapter 4 Intake and Exhaust System
4. Turbocharger
4 - 9 - 6 Abnormal sound or vibration
<Abnormal sound>
Possible cause
1) Excessively narrowed gas path due to
clogged nozzle in turbine housing or
reverse flow of blower discharge during
acceleration (generally called surging)
2) Contacting rotating parts
<Abnormal vibration>
Possible cause
1) Loose intake, exhaust or oil pipe
connection with the turbocharger
2) Chipping of turbine wheel or compressor
impeller caused by contacting between
rotating part and adjacent parts due to
damaged bearing, or invasion by foreign
matter
3) Unbalanced rotating part
Corrective action
• Disassemble and wash the turbocharger.
• Disassemble and repair or replace the
turbocharger.
Corrective action
• Check pipe connections of the
turbocharger and repair as needed.
• Disassemble and repair or replace the
turbocharger. If foreign matter has
invaded, completely remove it.
• Repair or replace the rotating part.
4-25
4LHA Ser