TURBOCHARGER
Troubleshooting the Turbocharger
12/05
6LY3 Service Manual
9-23
© 2007 Yanmar Marine International
TROUBLESHOOTING THE
TURBOCHARGER
When trouble develops with the turbocharger, it cannot perform as expected and the specified engine power
cannot be attained. Check that each engine system is functioning properly. When engine operation has been
confirmed, troubleshoot the turbocharger while referring to the following tables and take appropriate action.
Black Smoke
Insufficient Amount of Intake Air
Turbocharger Does Not Operate
Turbocharger Low Rotational Speed
Possible Cause
Correction
Air cleaner element is clogged.
Air inlet port is blocked.
Air leaks at the pipe connection.
Replace or clean the element.
Remove the obstruction.
Check and repair the pipe.
Possible Cause
Correction
The impurities contained in the oil precipitate at seal of the
turbine and hamper smooth rotation of the turbine rotor shaft.
Change the engine oil, disassemble and clean the turbocharger.
Bearing Seizure
• Insufficient oil feed or clogging of pipe.
• Oil temperature is too high.
• Imbalance of the rotating part.
• Insufficient warm-up operation or abrupt stopping of the
operation under load (No-load operation).
Disassemble and repair the turbocharger.
Inspect the engine oil system. Change the oil.
Replace or repair the rotating part.
Observe the operating precautions described in the
Operator’s
Manual
.
Contact or Failure of Turbine Rotor or the Compressor Impeller
• Over-rotation.
• Excessive rise of exhaust gas temperature.
• Ingestion of debris.
• Bearing wear.
• Improper assembly.
Inspect each engine system and repair as required.
Inspect the wastegate operation. Disassemble the turbine rotor
shaft and the compressor impeller. Inspect all the components.
Check the air cleaner and the engine. Repair as required.
Disassemble and repair the turbocharger.
Reassemble the turbocharger.
Possible Cause
Correction
Rotating speed does not pick up because of an exhaust gas
leak in front of the turbocharger.
Turbocharger fails to increase its speed because of a deformed
or blocked exhaust gas pipe.
Check the exhaust system and repair as required.
Repair or replace the exhaust system components.