Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
DEFINITION: The engine temperature lamp comes on and stays on, or temperature gauge 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? | -- | ||||||
2 | Fill the system to the specified level. Refer to Cooling System Maintenance Recommendations . Does the engine still overheat? | -- | System OK | |||||
3 | Check for kinked or pinched surge tank hoses, especially at the radiator. Are any surge tank hoses kinked or pinched? | -- | ||||||
4 |
Does the engine still overheat? | -- | 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? | -- | ||||||
6 | Repair or replace any loose, missing or damaged radiator air seals or deflectors. Refer to Radiator Air Baffle Assemblies and Deflectors . Does the engine still overheat? | -- | System OK | |||||
7 | Check the coolant concentration. Does the coolant concentration test correctly? | -- | ||||||
8 | Replace the coolant if necessary. Refer to Draining and Filling Cooling System . Does the engine still overheat? | -- | System OK | |||||
9 |
Important: Use the correct pressure cap. Check the system for loss of pressure. Refer to Cooling System Leak Testing . Is there a loss of pressure? | -- | ||||||
10 | Repair any leaks as necessary. Does the engine still overheat? | -- | System OK | |||||
11 | Check for a faulty engine coolant temperature sensor (ECT). Is the engine coolant temperature sensor faulty? | -- | ||||||
12 | Replace the ECT. Refer to Section 8A. Does the engine still overheat? | -- | System OK | |||||
13 | Check the radiator for any air flow obstructions or bent fins. Is there any airflow obstruction or bent fins? | -- | ||||||
14 |
Does the engine still overheat? | -- | System OK | |||||
15 | Check for any blocked cooling system passages. Are there any blocked cooling system passages? | -- | ||||||
16 |
Does the engine still overheat? | -- | System OK | |||||
17 | Check for an inoperative cooling fan. Is the cooling fan inoperative? | -- | ||||||
18 | Replace the cooling fan. Refer to Electric Cooling Fan . Does the engine still overheat? | -- | System OK | |||||
19 | Check for a thermostat that is stuck closed. Is the thermostat stuck closed? | -- | ||||||
20 | Replace the thermostat.
Does the engine still overheat? | -- | System OK | |||||
21 | Check for a faulty water pump. The impeller blades may be eroded or broken. Is the water pump faulty? | -- | -- | |||||
22 | Replace the water pump.
Does the engine still overheat? | -- | -- | System OK | ||||
