Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
DEFINITION: The engine temperature lamp comes ON and stays ON, or the temperature gage shows hot, or coolant overflows from the surge tank onto the ground while the engine is running. | ||||||||
1 | Check for a loss of coolant. Refer to Loss of Coolant. Is there a loss of coolant? | -- | Go to Step 2 | Go to Step 3 | ||||
2 | Fill the system to the specified level. Refer to Cooling System Draining and Filling. Does the engine still overheat? | -- | Go to Step 3 | System OK | ||||
3 | Check for kinked or pinched surge tank hoses, especially at the radiator. Are any surge tank hoses kinked or pinched? | -- | Go to Step 4 | Go to Step 5 | ||||
4 |
Does the engine still overheat? | -- | Go to Step 5 | System OK | ||||
5 | Check for loose, missing, or damaged radiator air seals or deflectors. Are there any loose, missing, or damaged radiator air seals or deflectors? | -- | Go to Step 6 | Go to Step 7 | ||||
6 | Repair or replace any loose, missing, or damaged radiator air seals or deflectors. Refer to Radiator Air Side Baffle and Deflector Replacement or Radiator Air Upper Baffle and Deflector Replacement. Does the engine still overheat? | -- | Go to Step 7 | System OK | ||||
7 | Check the coolant concentration. Does the coolant concentration test correctly? | -- | Go to Step 9 | Go to Step 8 | ||||
8 | Replace the coolant if necessary. Refer to Cooling System Draining and Filling. Does the engine still overheat? | -- | Go to Step 9 | System OK | ||||
9 |
Note: Use the correct pressure cap. Check the system for loss of pressure. Is there a loss of pressure? | -- | Go to Step 10 | Go to Step 11 | ||||
10 | Repair any leaks as necessary. Does the engine still overheat? | -- | Go to Step 11 | System OK | ||||
11 | Check for a faulty engine coolant temperature (ECT) sensor. Is the engine coolant temperature sensor faulty? | -- | Go to Step 12 | Go to Step 13 | ||||
12 | Replace the ECT. Refer to one of the following:
Does the engine still overheat? | -- | Go to Step 13 | System OK | ||||
13 | Check the radiator for any airflow obstructions or bent fins. Is there any airflow obstruction or bent fins? | -- | Go to Step 14 | Go to Step 15 | ||||
14 |
Does the engine still overheat? | -- | Go to Step 15 | System OK | ||||
15 | Check for any blocked cooling system passages. Are there any blocked cooling system passages? | -- | Go to Step 16 | Go to Step 17 | ||||
16 |
Does the engine still overheat? | -- | Go to Step 17 | System OK | ||||
17 | Check for an inoperative cooling fan. Is the cooling fan inoperative? | -- | Go to Step 18 | Go to Step 19 | ||||
18 | Replace the cooling fan. Refer to Cooling Fan and Shroud Replacement. Does the engine still overheat? | -- | Go to Step 19 | System OK | ||||
19 | Check for a thermostat that is stuck closed. Is the thermostat stuck closed? | -- | Go to Step 20 | Go to Step 21 | ||||
20 | Replace the thermostat. Refer to Engine Coolant Thermostat Replacement. Does the engine still overheat? | -- | Go to Step 21 | System OK | ||||
21 | Check for a faulty water pump. The impeller blades may be eroded or broken. Is the water pump faulty? | -- | Go to Step 22 | -- | ||||
22 | Replace the water pump. Refer to Water Pump Replacement. Does the engine still overheat? | -- | -- | System OK | ||||
