Engine speed not steady
Component
Cause
Action
Fuel injection equip‐
ment
Injector faulty
Replace (→ Page 88).
Speed sensor
Faulty
Replace.
Fuel system
Air in fuel system
Vent fuel system (→ Page 91)
ECU
Faulty
Contact Service.
Charge air temperature too high
Component
Cause
Action
Engine coolant
Engine coolant treatment incorrect
Check.
Intercooler
Contaminated
Contact Service.
Engine room
Air-intake temperature too high
Check fans and air supply / ventilation
ducts.
Charge-air pressure too low
Component
Cause
Action
Air supply
Air filter clogged
Check signal ring position of service in‐
dicator (→ Page 103).
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
Check signal ring position of service in‐
dicator (→ Page 103).
Fuel injection equip‐
ment
Injector faulty
Replace (→ Page 88).
Engine
Overloaded
Contact Service.
Blue exhaust gas
Component
Cause
Action
Engine oil
Too much oil in engine
Drain engine oil (→ Page 106).
Oil separator or oil-preseparator of
crankcase breather clogged
• Clean preseparator (→ Page 81);
• Replace oil separator element
(→ Page 82).
Exhaust turbocharg‐
er, cylinder head, pis‐
ton rings, cylinder lin‐
er
Faulty
Contact Service.
66 | Troubleshooting | MS150061/04E 2012-07
TIM-ID: 0000002555 - 003
