For 1990-2009 cars

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? | -- | Go to Step 2 | Go to Step 3
2 | Fill the system to the specified level. Refer to Engine Cooling System Specifications . 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 |

1. Relieve any kinks by rerouting the hoses.
2. Replace the hoses if necessary.

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 Baffle Assemblies and Deflectors . 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 | 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? | -- | 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 sensor (ECT). 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 procedures:

• | Engine Coolant Temperature Sensor Replacement in Engine Controls - 2.4L

• | Engine Coolant Temperature Sensor Replacement in Engine Controls - 3.1L

Does the engine still overheat?

--

Go to Step 13

System OK

13 | Check the radiator for any air flow obstructions or bent fins. Is there any airflow obstruction or bent fins? | -- | Go to Step 14 | Go to Step 15
14 |

1. Remove or relocate add-on parts that block air flow to the radiator.
2. Clean any debris from the radiator core.

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 |

1. Remove any obstruction.
2. Flush the cooling system as required. Refer to Flushing .
3. Refill the coolant. Refer to Cooling System Draining and Filling .

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 Engine Cooling Fan 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 one fo the following procedures:

• | Engine Coolant Thermostat Replacement

• | 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 one of the following procedures:

• | Auxiliary Water Pump Replacement

• | Auxiliary Water Pump Replacement

Does the engine still overheat?

--

--

System OK