Komatsu PC138USLC Operation & Maintenance Manual page 194

OPERATION
Engine Warm Up
NOTICE
Do not accelerate the engine suddenly until the warm-up operation has
been completed.
Do not run the engine at low idling or high idling under no load for more
than 20 minutes. This will have an adverse effect on the environment,
and will also have an adverse effect on the internal structure of the
engine. If it is necessary to run the engine at idling for more than 20
minutes, apply a load from time to time or run at a mid-range speed.
After the engine starts, do not start operating the machine immediately. First, carry out the following operations and
checks.
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) displays
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 monitor
displays the correct temperature.
(A) Display when temperature is correct: Monitor background
(B) Display when temperature is low: Monitor background (C)
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.
(C) is blue
is white
MACHINE OPERATIONS AND CONTROLS
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