Mitsubishi 6M70 - Cooling System Troubleshooting

14
14-5
Symptoms
Overheating (poor cooling) Overcooling Abnormal noise Excessive coolant loss
Reference Gr
Possible causes
Belt
Loose or damaged O O
Excessive tension O
Oil on belt O
Water pump
Incorrectly mounted water pump O O
Defective gasket O O
Defective bearing unit O O
Defective impeller O
Defective unit seal O O
Fit of bearing unit on flange and impeller too loose O O
Thermostat
Incorrectly mounted case O O
Defective gasket O O
Valve opening temperature too high
(valve remains closed)
O
Valve opening temperature too low (valve remains open) O
Leakage from coolant temperature sensor O O
Radiator
Clogged core O
Cracked core and/or separation in welds O O
Automatic cooling fan
coupling
Defective bearing O O
Damaged bimetal O
Contaminated bimetal O O
Silicon oil leakage O O
Oil cooler
Incorrectly mounted oil cooler O O
Gr12
Defective gasket O O
Cylinder head
Incorrectly mounted cylinder head O O
Gr11
Defective gasket O O
Poorly airtight pressure cap O
Insufficient coolant amount, contaminated coolant O
Clogged or scaled coolant passage O
Incorrectly connected hoses O O
Excessively low exterior temperature O
Exhaust gas recircula-
tion related
Defective gasket O O
Gr17
Incorrectly mounted exhaust gas recirculation piping O O
Air compressor
Defective gasket O O
Gr11
Incorrectly mounted water pipe O O
TROUBLESHOOTING