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Engine Overheating

Engine Overheating


Step Action 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

Go to

2

Fill the system to the specified level.

Does the engine still overheat?

Go to

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

Go to

4


1. Relieve any kinks by rerouting the hoses.

2. Replace the hoses, if necessary.


Does the engine still overheat?

Go to

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

Go to

6

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

Does the engine still overheat?

Go to

System OK

7

Check the coolant concentration.

Does the coolant concentration test correctly?

Go to

Go to

8

Replace the coolant, if necessary.

Does the engine still overheat?

Go to

System OK

9

Note

Use the correct pressure cap.


Check the system for loss of pressure. Refer to Pressure Cap Testing .

Is there a loss of pressure?

Go to

Go to

10

Repair any leaks, as necessary.

Does the engine still overheat?

Go to

System OK

11

Check for a faulty engine coolant temperature sensor.

Is the engine coolant temperature sensor faulty?

Go to

Go to

12

Replace the engine coolant temperature sensor. Refer to:


• Engine Coolant Temperature Sensor Replacement for the 2.0L engine

• Engine Coolant Temperature Sensor Replacement for the 2.0L (Diesel) engine

• Engine Coolant Temperature Sensor Replacement for the 2.8L engine


Does the engine still overheat?

Go to

System OK

13

Check the radiator for any air flow obstructions or bent fins.

Is there any airflow obstruction or bent fins?

Go to

Go to

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

System OK

15

Check for any blocked cooling system passages.

Are there any blocked cooling system passages?

Go to

Go to

16


1. Remove any obstruction.

2. Flush the cooling system, as required.

3. Refill the coolant.


Does the engine still overheat?

Go to

System OK

17

Check for an inoperative cooling fan.

Is the cooling fan inoperative?

Go to

Go to

18

Replace the cooling fan. Refer to Engine Coolant Fan Motor Replacement (Diesel) Engine Coolant Fan Motor Replacement (LAU/A28NER)

Does the engine still overheat?

Go to

System OK

19

Check for a thermostat that is stuck closed.

Is the thermostat stuck closed?

Go to

Go to

20

Replace the thermostat. Refer to Engine Coolant Thermostat Replacement (Diesel) Engine Coolant Thermostat Replacement (LLU/A16LET) Engine Coolant Thermostat Replacement (LHU/A20NFT)

Does the engine still overheat?

Go to

System OK

21

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

Is the water pump faulty?

Go to

-

22

Replace the water pump. Refer to Water Pump Replacement (Diesel) Water Pump Replacement (LAU/A28NER) Water Pump Replacement (LHU/A20NFT) .

Does the engine still overheat?

-

System OK