Coolant Temperature Rises Too High (Overheating) - Komatsu PC200-8M0 Shop Manual

600 Troubleshooting of engine (S-mode)
S-14 Coolant temperature rises too high (overheating)
S-14 Coolant temperature rises too high (overheating)
General causes why coolant temperature rises too high
q Lack of cooling air (deformation or damage of fan)
q
Drop in heat dissipation efficiency
q
Problem in coolant circulation system
Check recent repair history.
Machine opera-
Operated for long period
tion hours
Suddenly occurred.
Overheating
Tends to occur always.
Indiacates quick temperature rise.
Coolant temper-
ature gauge:
Does not go down from red range.
Radiator coolant level monitor indicates drop of coolant level.
Engine oil level has risen and oil is milky.
Fan belt tension is low.
When fan pulley is turned, it has play.
Milky oil is floating on coolant.
Unusual air bubbles are found in radiator or coolant spurts.
When light bulb is held behind radiator core, no light passes through.
Radiator shroud and inside of underguard are clogged with dirt or mud.
Coolant is leaking because of cracks in hose or loose clamps.
Coolant flows out from radiator overflow hose.
Fan belt whines under sudden acceleration.
Hydraulic oil temperature gauge enters red range faster than engine coolant
temperature gauge.
When compression pressure is measured, it is found to be low.
Check cylinder.
Check oil cooler.
Temperature difference between upper and lower tanks of radiator is large.
When operation of thermostat is tested, it does not open at specified opening
temperature.
Temperature difference between upper and lower tanks of radiator is slight.
Check radiator core.
When operation of radiator cap is tested, its opening pressure is low.
Check fan belt and pulley.
When coolant temperature is measured, it is found to be normal.
PC200, 200LC, 220, 220LC-8M0
Causes
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Remedy
SEN06140-00
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21
40-600