DEFINITION: The cooling system is loosing coolant either internally or externally.

Were you sent here from Symptoms or another diagnostic table?

Go to Step 2

Go to Symptoms - Engine Cooling

Diagnose or repair any present DTCs. Refer to Diagnostic System Check - Vehicle in Vehicle DTC Information.

Is the action complete?

Go to Step 3

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Inspect the coolant level.

Is the coolant at the proper level?

Go to Step 6

Go to Step 4

Fill the cooling system to the proper level. Refer to Cooling System Draining and Filling .

Is the action complete?

Go to Step 5

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If the engine is suspected to have a coolant leak into a cylinder, the coolant can hydraulically lock the engine.

Does the engine crankshaft rotate?

Go to Step 6

Go to Step 26

Engine overheating can cause a loss of coolant.

Is the engine overheating?

Go to Step 27

Go to Step 7

Extended operation with a low coolant level can cause engine internal component failure.

Is the engine knocking?

Go to Step 29

Go to Step 8

1. Idle the engine at normal operating temperature.
2. Inspect for heavy white smoke coming out of the exhaust pipe.

Is a heavy white smoke present from the exhaust pipe?

Go to Step 9

Go to Step 10

Coolant in the exhaust system creates a distinctive, burning coolant odor in the exhaust.

Condensation in the exhaust system can cause an odorless white smoke during engine warm up.

Does the white smoke have a burning coolant type odor?

Go to Step 28

Go to Step 10

With the engine idling, inspect the coolant recovery system.

Does the surge tank discharge coolant while the engine is idling?

Go to Step 15

Go to Step 11

Visually inspect the hoses, pipes and hose clamps at the following locations:

Are any of the hoses, clamps or pipes leaking?

Go to Step 20

Go to Step 12

Visually inspect the following components:

Are any of the listed components leaking?

Go to Step 20

Go to Step 13

1. Pressure test the cooling system. Refer to Cooling System Leak Testing .
2. With the cooling system pressurized, visually inspect the components listed in steps 11 and 12.

Are any leaks present?

Go to Step 20

Go to Step 14

Pressure test the coolant pressure cap. Refer to Pressure Cap Testing .

Does the coolant pressure cap hold pressure?

Go to Step 16

Go to Step 21

Pressure test the coolant pressure cap. Refer to Pressure Cap Testing .

Does the coolant pressure cap hold pressure?

Go to Step 30

Go to Step 21

Inspect for the following conditions:

Is coolant present?

Go to Step 22

Go to Step 17

Inspect the underside of the engine oil fill cap for a gray/white milky substance.

Is there a milky substance on under the oil fill cap?

Go to Step 18

Go to Step 19

Inspect the engine oil fluid level indicator for a gray/white milky substance.

Is there a milky substance on the engine oil fluid level indicator?

Go to Step 28

Go to Step 19

Inspect the automatic transmission oil fluid level indicator, if equipped, for a gray/white milky substance.

Is there a milky substance on the automatic transmission fluid level indicator?

Go to Step 23

Go to Step 31

Repair or replace the leaking component. Refer to the appropriate repair.

Is the repair complete?

Go to Step 31

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Replace the coolant pressure cap.

Is the repair complete?

Go to Step 31

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Replace the heater core. Refer to Heater Core Replacement in Heating, Ventilation and Air Conditioning.

Is the repair complete?

Go to Step 31

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1. Remove the transmission oil cooler lines from the radiator.
2. Pressure test the cooling system. Refer to Cooling System Leak Testing .
3. Inspect the transmission oil cooler for coolant.

Is coolant present?

Go to Step 24

Go to Step 25

1. Replace the radiator. Refer to Radiator Replacement .
2. Service the automatic transmission. Refer to Engine Coolant/Water in Transmission in Automatic Transmission - 5L40-E/5L50-E.

Is the repair complete?

Go to Step 31

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Install the cooler lines to the radiator.

Is the action complete?

Go to Step 31

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Repair the engine no crank condition. Refer to Engine Will Not Crank - Crankshaft Will Not Rotate in Engine Mechanical - 2.8L (LP1) or Engine Will Not Crank - Crankshaft Will Not Rotate in Engine Mechanical - 3.6L (LY7).

Is the repair complete?

Go to Step 31

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Repair the engine overheating condition. Refer to Engine Overheating .

Is the repair complete?

Go to Step 31

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Repair the engine internal coolant leak. Refer to the following procedures:

Is the repair complete?

Go to Step 31

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Repair the engine knock. Refer to Lower Engine Noise, Regardless of Engine Speed in Engine Mechanical - 2.8L (LP1) or Lower Engine Noise, Regardless of Engine Speed in Engine Mechanical - 3.6L (LY7).

Is the repair complete?

Go to Step 31

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Repair the combustion pressure in the cooling system problem. Refer to Cylinder Leakage Test in Engine Mechanical - 2.8L (LP1) or Cylinder Leakage Test in Engine Mechanical - 3.6L (LY7).

Is the repair complete?

Go to Step 31

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Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2

DEFINITION: The cooling system is losing coolant either internally or externally.

Were you sent here from Symptoms or another diagnostic?

Go to Step 2

Go to Symptoms - Engine Cooling

Diagnose and repair any present DTCs. Refer to Diagnostic System Check - Vehicle in Vehicle DTC Information.

Is the action complete?

Go to Step 3

--

Inspect the coolant level.

Is the coolant at the proper level?

Go to Step 6

Go to Step 4

Fill the cooling system to the proper level. Refer to Cooling System Draining and Filling .

Is the action complete?

Go to Step 5

--

If the engine is suspected to have a coolant leak into a cylinder, the coolant can hydraulically lock the engine.

Does the engine crankshaft rotate?

Go to Step 6

Go to Step 22

Engine overheating can cause a loss of coolant.

Is the engine overheating?

Go to Step 23

Go to Step 7

Extended operation with a low coolant level can cause engine internal component failure.

Is the engine knocking?

Go to Step 25

Go to Step 8

1. Idle the engine at normal operating temperature.
2. Inspect for heavy white smoke coming out of the exhaust pipe.

Is a heavy white smoke present from the exhaust pipe?

Go to Step 9

Go to Step 10

Coolant in the exhaust system creates a distinctive, burning coolant odor in the exhaust.

Condensation in the exhaust system can cause an odorless white smoke during engine warm up.

Does the white smoke have a burning coolant type odor?

Go to Step 24

Go to Step 10

With the engine idling, inspect the surge tank.

Does the coolant recovery system discharge coolant while the engine is idling?

Go to Step 15

Go to Step 11

Visually inspect the hoses, pipes and hose clamps at the following locations:

Are any of the hoses, clamps or pipes leaking?

Go to Step 19

Go to Step 12

Visually inspect the following components:

Are any of the listed components leaking?

Go to Step 19

Go to Step 13

1. Pressure test the cooling system. Refer to Cooling System Leak Testing .
2. With the cooling system pressurized, visually inspect the components listed in steps 11 and 12.

Are any leaks present?

Go to Step 19

Go to Step 14

Pressure test the coolant pressure cap. Refer to Pressure Cap Testing .

Does the coolant pressure cap hold pressure?

Go to Step 16

Go to Step 20

Pressure test the coolant pressure cap. Refer to Pressure Cap Testing .

Does the coolant pressure cap hold pressure?

Go to Step 26

Go to Step 20

Inspect for the following conditions:

Is coolant present?

Go to Step 21

Go to Step 17

Inspect the underside of the engine oil fill cap for a gray/white milky substance.

Is there a milky substance on under the oil fill cap?

Go to Step 18

Go to Step 19

Inspect the engine oil level indicator for a gray/white milky substance.

Is there a milky substance on the engine oil level indicator?

Go to Step 24

Go to Step 19

Repair or replace the leaking component. Refer to the appropriate repair.

Is the repair complete?

Go to Step 27

--

Replace the coolant pressure cap.

Is the repair complete?

Go to Step 27

--

Replace the heater core. Refer to Heater Core Replacement in Heating, Ventilation and Air Conditioning.

Is the repair complete?

Go to Step 27

--

Repair the engine no crank condition. Refer to Engine Will Not Crank - Crankshaft Will Not Rotate in Engine Mechanical - 2.8L (LP1), Engine Will Not Crank - Crankshaft Will Not Rotate in Engine Mechanical - 3.6L (LY7), or Engine Will Not Crank - Crankshaft Will Not Rotate in Engine Mechanical - 5.7L.

Is the repair complete?

Go to Step 27

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Repair the engine overheating condition. Refer to Engine Overheating .

Is the repair complete?

Go to Step 27

--

Repair the engine internal coolant leak. Refer to Coolant in Combustion Chamber or Coolant in Engine Oil in Engine Mechanical - 2.8L (LP1), Coolant in Combustion Chamber or Coolant in Engine Oil in Engine Mechanical - 3.6L (LY7), or Coolant in Combustion Chamber or Coolant in Engine Oil in Engine Mechanical - 5.7L.

Is the repair complete?

Go to Step 27

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Repair the engine knock. Refer to Lower Engine Noise, Regardless of Engine Speed in Engine Mechanical - 2.8L (LP1), Lower Engine Noise, Regardless of Engine Speed in Engine Mechanical - 3.6L (LY7), or Lower Engine Noise, Regardless of Engine Speed in Engine Mechanical - 5.7L.

Is the repair complete?

Go to Step 27

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Repair the combustion pressure in the cooling system problem. Refer to Cylinder Leakage Test in Engine Mechanical - 2.8L (LP1), Cylinder Leakage Test in Engine Mechanical - 3.6L (LY7), or Cylinder Leakage Test in Engine Mechanical - 5.7L.

Is the repair complete?

Go to Step 27

--

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2