Troubleshooting The Turbocharger; Black Smoke - Yanmar 6LY3 series Service Manual

Troubleshooting the Turbocharger

12/05
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
Possible Cause
Air cleaner element is clogged.
Air inlet port is blocked.
Air leaks at the pipe connection.
Turbocharger Does Not Operate
Possible Cause
The impurities contained in the oil precipitate at seal of the
turbine and hamper smooth rotation of the turbine rotor shaft.
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).
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.
Turbocharger Low Rotational Speed
Possible Cause
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.
6LY3 Service Manual
Replace or clean the element.
Remove the obstruction.
Check and repair the pipe.
Change the engine oil, disassemble and clean the turbocharger.
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.
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.
Check the exhaust system and repair as required.
Repair or replace the exhaust system components.
© 2007 Yanmar Marine International
TURBOCHARGER
Correction
Correction
Correction
9-23