DEFINITION: Engine temperature lamp comes ON and stays ON, or the temperature gage shows hot, or coolant overflows from the coolant recovery reservoir onto the ground while the engine is running.

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

Check the condenser, radiator and auxiliary coolers for any obstructions or bent fins that would prevent air flow through the radiator.

Is there any airflow obstruction or bent fins?

Go to Step 3

Go to Step 4

1. Remove any debris that may cause an air flow obstruction.
2. Remove or relocate aftermarket add-on components that block air flow to the radiator.

Does the engine still overheat?

Go to Step 4

Go to Step 17

1. Inspect for loose, damaged, and/or missing of the following:

•	The A/C condenser seals

•	The front air deflector

•	The side seals

2. Repair the system as necessary.

Does the engine still overheat?

Go to Step 5

Go to Step 17

Inspect for an inoperative fan clutch. Refer to Fan Clutch Diagnosis.

Does the engine still overheat?

Go to Step 6

Go to Step 17

Check for loss of coolant. Refer to Loss of Coolant.

Does the engine still overheat?

Go to Step 7

Go to Step 17

Check for kinked or pinched hoses.

Are any cooling hoses kinked or pinched?

Go to Step 8

Go to Step 9

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

Does the engine still overheat?

Go to Step 9

Go to Step 17

Using the J 23688 Coolant and Battery Fluid Tester, test for insufficient coolant concentration.

Does the coolant concentration test correctly?

Go to Step 11

Go to Step 10

Replace the coolant, if necessary. Refer to Cooling System Draining and Filling.

Does the engine still overheat?

Go to Step 11

Go to Step 17

Inspect for blocked cooling system passages.

Are the cooling system passages blocked?

Go to Step 12

Go to Step 13

Remove any obstructions by flushing the cooling system. Refer to Flushing.

Does the engine still overheat?

Go to Step 13

Go to Step 17

Inspect the drive belt tensioner. Refer to Drive Belt Tensioner Diagnosis for the 3.7L engine and Drive Belt Tensioner Diagnosis for the 4.8L, 5.3L, 6.0L, 6.2L or 7.0L engine.

Does the engine still overheat?

Go to Step 14

Go to Step 17

Inspect the thermostat foe proper operation. Refer to Thermostat Diagnosis.

Does the engine still overheat?

Go to Step 15

Go to Step 17

Replace the radiator. Refer to Radiator Replacement.

Does the engine still overheat?

Go to Step 16

Go to Step 17

Replace the engine water pump. Refer to Water Pump Replacement.

Did you complete the repair?

Go to Step 17

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2