MTU 12V4000Gx5S Series Operating Instructions Manual page 188

Black/gray exhaust gas
Cause
Air filter clogged
Injector faulty
Engine: Excessive load
DPF element faulty or leaking
Blue exhaust gas
Cause
Too much engine oil in the engine
Oil separator of crankcase
breather contaminated
Exhaust turbocharger, cylinder
head, piston rings or cylinder liner
defective
White exhaust gas
Cause
Engine is not at operating
temperature
Water in fuel
Intercooler leaking
Water condenses and forms an
odorless vapor
Uncombusted fuel condenses and
forms a strong-smelling vapor
Yellow/brown exhaust gas
Cause
RA dosing release temperature for
EGAT not reached
Insufficient RA dosing although
engine and EGAT are warm
enough
Severe component sooting
Cause
Gasket not tight or faulty
component pressurized with
exhaust gas
186 | Troubleshooting | MS15065/01E 2019-01
Corrective action
u Check signal ring position of service indicator (→ Page 254).
u Replace (→ Page 212).
u Contact Service.
u Contact Service.
Corrective action
u Drain engine oil (→ Page 268).
u Replace filter (→ Page 197).
u Contact Service.
Corrective action
u Run engine up to operating temperature.
u Check fuel system on fuel prefilter.
Drain water from fuel prefilter (not switchable) (→ Page 233).
Drain fuel prefilter (switchable) (→ Page 235).
u Contact Service.
1. Run to warm up engine and EGAT following warm-up table as
necessary.
2. May occur in cold ambient conditions (non-critical). Follow auxiliary
heating table.
1. Run to warm up engine and EGAT following warm-up table as
necessary.
2. May occur in cold ambient conditions (non-critical). Follow auxiliary
heating table.
Corrective action
u Run engine up to operating temperature.
1. Check for fault message.
2. Contact Service.
Corrective action
u Replace gaskets; replace faulty component.