Engine speed not steady
Component
Cause
Action
Fuel injection equip‐
ment
Injector faulty
Replace (→ Page 48).
Speed sensor
Faulty
Contact Service.
Fuel system
Air in fuel system, if fault occurs after
filling the system.
Vent fuel system (→ Page 56).
Engine governor
Faulty
Contact Service.
Charge-air temperature too high
Component
Cause
Action
Engine coolant
Engine coolant treatment incorrect
Check (MTU test kit).
Intercooler
Contaminated
Contact Service.
Engine room
Air-intake temperature too high
Check fan;
check air inlet/outlet ducts.
Charge-air pressure too low
Component
Cause
Action
Air supply
Air filter clogged
Replace air filter (see manufacturer's
documentation).
Intercooler
Contaminated
Contact Service.
Exhaust turbocharger Faulty
Contact Service.
Coolant leaks at intercooler
Component
Cause
Action
Intercooler
Leaking, major coolant discharge
Contact Service.
Black exhaust gas
Component
Cause
Action
Air supply
Air filter clogged
Replace air filter (see manufacturer's
documentation).
Fuel injection equip‐
ment
Injector faulty
Replace (→ Page 48).
Engine
Overloaded
Contact Service.
Blue exhaust gas
Component
Cause
Action
Engine oil
Too much oil in engine
Drain engine oil (→ Page 70).
Oil mist fine separator of crankcase
breather clogged
Replace (→ Page 43).
Exhaust turbocharger
Cylinder head
Piston rings
Cylinder liner
Faulty
Contact Service.
MS150095/01E 2012-08 | Troubleshooting | 39
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