Komatsu PC450-8, Operation & Maintenance Manual, Page: 198 / 474

MACHINE OPERATIONS AND CONTROLS
OPERATION
3-132
1. This machine is equipped with an automatic engine warm-up system, so if the engine water temperature is
below 30 °C after the engine is started, the engine warm-up operation starts automatically. When the engine
automatic warm-up operation starts, the engine speed is maintained at a speed higher than the normal low
idling speed.
If the engine water temperature goes above 30 °C or if the warm-up operation has been continued for more
than 10 minutes, the automatic warm-up operation is cancelled and the engine speed drops to the normal low
idling speed.
2. Check that engine coolant temperature monitor (1) dis-
plays the correct temperature.
If it displays low temperature, use the procedure in Step 3
to carry out additional warm up of the engine until the mon-
itor displays the correct temperature.
(A) Display when temperature is correct: Monitor back-
ground (C) is blue
(B) Display when temperature is low: Monitor background
(C) is white
3. Turn fuel control dial (2) to a point midway between low
idling (MIN) and full speed (MAX), run the engine under no
load at a mid-range speed until engine coolant temperature
monitor (1) displays the correct temperature.
(A) Display when temperature is correct: Monitor background
(C) is blue
(B) Display when temperature is low: Monitor background (C)
is white
If the engine coolant temperature monitor displays the correct temperature, the engine warm-up operation is com-
pleted.
After checking that the engine coolant temperature monitor displays the correct temperature, carry out the warm-
up operation for the hydraulic equipment.
NOTICE
Canceling automatic warm-up operation
If it becomes necessary in an emergency to cancel the automatic warm-up operation or to lower the
engine speed to low idle, do as follows.