Mitsubishi 4DQ50 Service Manual page 75

Probable cause
Possible remedy
Insufficient coolant Insufficient coolant
Add water to prescribed level.
Overheating
Water leak in unit seal of water
Replace part (s)
pump
'Crack in crankcase water jacket
Replace crankcase.
Water leak in other parts
Check, and repaU.
Failure of radiator to
Air in cooling system
Bleed aU by loosening aU bleed
dissipate heat properly
plug, drain plug, or hose clamp.
Rust and scale deposited in Flush.
radiator
Dust and dirt around radiator Flush.
Slippage of fan belt
Adjust' belt tension.
Inoperative thermostat
Replace.
(kept closed)
Radiator dissipates heat
Extremely low atmospheric
excessively temperature
Uncovered radiator
Cover radiator.
Inoperative thermostat Replace part (s).
(kept open)
Jammed moving parts
Sticking cylinders, pistons RepaU and replace part (s) if
or piston rings necessary.
Sticking main bearings and
RepaU and replace part (s) if '
crankpin bearings
necessarr·
Sticking cam bushing and
idler bushing
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