Yanmar 4LHA-HTP Operation Manual page 500

Chapter 4 Intake and Exhaust System
4. Turbocharger
4-9 Troubleshooting
Sufficient turbocharger performance and required engine output cannot be obtained if there is any
fault. In such a case, first check each engine part to see if there is any fault. Then, inspect the
turbocharger for troubleshooting according to the procedure shown below.
4 - 9 - 1 Excessively dense exhaust smoke
<lnsufficient intake air amount>
Possible cause
1) Clogged air cleaner element
2) Blocked air intake port
3) Leak from a joint in intake line
<Turbocharger operation failure>
Possible cause
1) Deposit of impurities in oil sticking on the
turbine side seal portion to hamper
smooth turbine shaft rotation
2) Bearing seizure
• Insufficient lubrication or clogged
lubrication piping
• Excessively high oil temperature
• Unbalanced rotating part
• Insufficient warming up or sudden
stop from loaded operation (no-load
operation)
3) Contact or breakdown of turbine wheel or
compressor impeller
• Over speed
• Excessive exhaust temperature rise
• Foreign matter invasion
• Worn bearing
• Faulty assembly
Corrective action
Replace or wash the element.
Remove obstruction.
Inspect and repair.
Corrective action
Turbocharger overhaul (disassembly and
washing) and engine oil replacement
Turbocharger overhaul (disassembly and
repair)
Inspect the oil system of the engine and
repair faulty parts and replace the engine
oil.
Replace or wash the faulty rotating part.
Strictly observe instructions in the
operation manual.
Inspect and repair faulty engine parts.
Completely remove foreign matter after
disassembling. Inspect the air cleaner
and engine parts and repair as needed.
Disassemble turbocharger for repair.
Reassemble.
4-23
i 4LHA Serie