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Engine does not reach nominal speed
Component
Probable cause
Task
Fuel supply
Fuel prefilter clogged
Replace (→ Page 90).
Easy-change fuel filter clogged
Replace (→ Page 84).
Air supply
Air filter clogged
Check signal ring position of service in‐
Fuel injection equip‐
ment
Injector defective
Replace (→ Page 77).
Engine wiring
Defective
Check (→ Page 125).
Engine
Overloaded
Contact Service.
Engine speed not steady
Component
Probable cause
Task
Fuel injection equip‐
ment
Injector defective
Replace (→ Page 77).
Speed sensor
Defective
Contact Service.
Fuel system
Not vented
Engine Governor
Defective
Contact Service.
Charge-air temperature too high
Component
Probable cause
Task
Engine coolant
Incorrect coolant concentration
Check (MTU test kit).
Intercooler
Contaminated
Contact Service.
Engine room
Air-intake temperature too high
Check fans and air supply / ventilation
ducts.
Charge air pressure too low
Component
Probable cause
Task
Air supply
Air filter clogged
Check signal ring position of service in‐
Intercooler
Contaminated
Contact Service.
Exhaust turbocharger Defective
Contact Service.
Coolant leaks on intercooler
Component
Probable cause
Task
Intercooler
Leaking, major coolant discharge
Contact Service.
Exhaust gas black
Component
Probable cause
Task
Air supply
Air filter clogged
Check signal ring position of service in‐
Fuel injection equip‐
ment
Injector defective
Replace (→ Page 77).
Engine
Overloaded
Contact Service.
MS150064/01E 2011-11 | Troubleshooting | 49
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