MTU 12V4000M73 series Operating Instructions Manual page 132

Black exhaust gas.
Cause
Overload.
Air filter clogged.
Injector defective.
Blue exhaust gas
Cause
Too much engine oil in the engine.
Oil separator of crankcase
breather contaminated.
Exhaust turbocharger defective.
Cylinder head defective.
Piston rings or cylinder liner
defective.
White exhaust gas
Cause
Engine is not at operating
temperature.
Intercooler leaky.
130 | Troubleshooting | MS150045/03E 2018-08
Corrective action
u Reduce load.
1. Check signal ring position of service indicator (→ Page 211).
2. Replace air filter (→ Page 209).
u Replace (→ Page 185).
Corrective action
u Drain engine oil (→ Page 215).
u Replace oil separator (→ Page 175).
u Replace (→ Instructions for Exchange of Sub-assemblies).
1. Check cylinder compression.
2. Replace cylinder head (→ Instructions for Exchange of Sub-
assemblies).
1. Check cylinder compression.
2. Carry out endoscopic examination of cylinder liner (→ Page 171).
3. Replace piston rings (→ Instructions for Exchange of Sub-
assemblies).
4. Replace cylinder liner (→ Instructions for Exchange of Sub-
assemblies).
5. Contact Service.
Corrective action
u Run engine to reach operating temperature.
1. Check condensate drain for coolant discharge and obstruction
(→ Page 207).
2. Replace intercooler (→ Instructions for Exchange of Sub-
assemblies).