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

Special Tools

GE-26568 Coolant and Battery Fluid Tester

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 2

Go to Step 3

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 3

System OK

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 4

Go to Step 5

Repair or replace any loose, missing, or damaged radiator air seals or deflectors.

Does the engine still overheat?

Go to Step 5

System OK

Check for an inoperative cooling fan..

Is the cooling fan inoperative?

Go to Step 6

Go to Step 7

Repair or replace the cooling fan(s) as necessary. Refer to Cooling Fan and Shroud Replacement .

Does the engine still overheat?

Go to Step 7

System OK

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

Does the engine still overheat?

Go to Step 8

System OK

Check for kinked or pinched cooling hoses.

Does the engine still overheat?

Go to Step 9

Go to Step 10

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

Does the engine still overheat?

Go to Step 10

System OK

Using GE-26568 Coolant and Battery Fluid Tester , check the coolant concentration.

Does the coolant concentration test correctly?

Go to Step 12

Go to Step 11

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

Does the engine still overheat?

Go to Step 12

System OK

Check for any blocked cooling system passages.

Are there blocked cooling system passages?

Go to Step 13

Go to Step 14

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

Does the engine still overheat?

Go to Step 14

Go to Step 19

Inspect the water pump drive belt.

Does the engine still overheat?

Go to Step 15

System OK

Check for a faulty thermostat. Refer to Thermostat Diagnosis .

Does the engine still overheat?

Go to Step 16

System OK

Replace the radiator. Refer to Radiator Replacement .

Does the engine still overheat?

Go to Step 17

System OK

Check for a faulty water pump. The impeller blades may be eroded or broken.

Is the water pump faulty?

Go to Step 18

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Replace the water pump. Refer to Water Pump Replacement .

Does the engine still overheat?

Go to Step 19

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Operate the system to verify the repair.

Did you correct the condition?

System OK

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