The coolant hoses are faulty.

Replace the hoses, as necessary.

Refer to Radiator Outlet Hose Replacement or Radiator Inlet Hose Replacement .

The coolant hose clamps are faulty.

Replace the clamps, as necessary.

Refer to Radiator Outlet Hose Replacement or Radiator Inlet Hose Replacement .

The heater hoses are faulty.

Replace the hoses, as necessary.

Refer to Heater Pipes Replacement in HvAC.

The coolant drain plugs are loose.

Tighten the coolant drain plugs.

The radiator drain cock is loose.

Tighten the radiator drain cock as needed.

Refer to Cooling System Draining and Filling .

The radiator core is leaking.

Repair the radiator core as needed.

Refer to Radiator Replacement .

The radiator cap is faulty.

Replace the radiator cap.

Refer to Cooling System Leak Testing .

The radiator is restricted.

Repair the restriction as needed.

Refer to Engine Overheating .

The radiator shroud or the baffles are missing.

Install the correct radiator shroud or baffles.

Refer to Fan Shroud Replacement or Radiator Lower Mounting Panel Replacement .

The water pump is faulty.

Replace the water pump.

Refer to Water Pump Replacement .

The head gasket is leaking.

Repair or replace the head gasket. Refer to the Isuzu Unit Repair Manual.