11 TROUBLESHOOTING
Mitsubishi Diesel Engine S12R OPERATION & MAINTENANCE MANUAL
185
Pub. No. 291Y1-40720 Revision: 5
Exhaust Smoke is Black or Dark Grey
Table 11-6 Exhaust Smoke is Black or Dark Grey (1/2)
Problem Cause Remedies
Reference
Page
Exhaust Smoke
is Black or Dark
Grey
Fuel System Improper fuel
properties
• Change with appropriate fuel. 103
Fuel feed pump
malfunction
• Contact your MHIET dealer. 10
Fuel injection
pump malfunction
Fuel injection noz-
zle malfunction
Faulty fuel injec-
tion timing
• Check fuel injection pump drive
coupling.
-
• Contact your MHIET dealer. 10
Uneven fuel injec-
tion volume
• Check ignition sound, exhaust
temperature and the balance
between left and right banks.
-
• Contact your MHIET dealer. 10
Lubrication
System
Combustion of en-
gine oil
• Check engine oil properties.
• Engine oil level - Check
149
• Contact your MHIET dealer. 10
Inlet and
Exhaust
Systems
Insufficient
amount of intake
air
• Turbocharger - Check 165
• Clean, check and replace pre-
cleaner.
166
• Clean, check and replace air
cleaner element.
• Check intake air pressure and
leakage of intake air.
• Check intake air temperature and
ventilation system.
167
• Contact your MHIET dealer. 10
Increase of ex-
haust resistance
• Turbocharger - Check 165
• Check exhaust pipes, muffler and
silencer.
165
• Contact your MHIET dealer. 10