TM 9-4940-568-20
2-64
Table 2-7. Engine Troubleshooting (CONT).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
18. COOLANT TEMPERATURE ABOVE NORMAL (165 F – 195 F) – GRADUAL
OVERHEAT (CONT).
Temperature sending unit or gage malfunctioning.
Replace temperature sending unit (Para 8-34) or gage (Para 8-44).
Thermostat malfunctioning or incorrect.
Check/replace the thermostat (Para 8-33).
Air in the cooling system.
If coolant is aerated, perform cooling system service (Para 8-25).
Water pump malfunctioning.
Check/replace the water pump (Para 8-28).
Cooling passages in radiator, head, head gasket or block plugged.
Flush the system and fill with clean coolant (Para 8-25).
