4.7 After stopping the engine
Preconditions
☑
MTU Preservation and Represervation Instructions (A001070/..) are available.
NOTICE
Engine coolant with inadequate freeze protection. Water remaining in the pressure sensors freezes
at temperatures below 0 °C.
Risk of sensor damage!
• Remove pressure sensors and shake off residual water.
After stopping the engine
Item
Action
Coolant circuit
Drain engine coolant (→ Page 128) if
• freezing temperatures are expected, the engine is to remain out of service
for an extended period, but engine coolant has no antifreeze additive.
• the engine room is not heated.
• the coolant is not kept at a suitable temperature.
• the antifreeze concentration is insufficient for the engine-room tempera-
ture.
• the antifreeze concentration is 50% and the engine-room temperature is
below -40 °C.
Engine control system
Switch off (see manufacturer's documentation).
Air intake and exhaust sys-
tem
If the engine is to be taken out of service for longer than 1 week, seal the
engine on the air and exhaust side.
If the engine is to be taken out of service for longer than 1 month, it has to
be preserved (→ MTU Preservation and Represervation Instructions
A001070/..).
HP system (injector noise)
The pressure is released in the system by means of the function "Blank Shot
Afterrun":
• Injectors are energized.
• A small injection quantity is diverted into the injector return line without
the nozzle needle opening (actuation of the servo valve on the injector
side, which does not result in injection into the combustion chamber).
Explanation: The injectors do not leak permanently, which is why the pres-
sure applied in the system during engine stop is maintained. Pressure is only
released through actuation of the injectors. When actuated, the switched
quantity of the servo valve and the injection quantity are discharged. This
procedure results in injector noise.
Depressurizing (pressure <400 bar) is necessary for the following reasons:
• Limitation of load on high-pressure pumps during start
• Safety during assembly activities
58 | Operation | MS150118/01E 2015-05
TIM-ID: 0000054740 - 002
