GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2007 🢒 VUE - FWD 🢒 Engine 🢒 Engine Cooling 🢒 Loss of Coolant

Step

Action

Yes

No

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

1

Were you sent here from Symptoms or another diagnostic table?

Did you perform the Diagnostic Starting Point-Engine Cooling?

Go to Step 2

Go to Diagnostic Starting Point - Engine Cooling

2

Inspect the coolant level.

Is the coolant at the proper level?

Go to Step 5

Go to Step 3

3

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

Is the action complete?

Go to Step 4

--

4

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 5

Go to Step 25

5

Engine overheating can cause a loss of coolant.

Is the engine overheating?

Go to Step 26

Go to Step 6

6

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

Is the engine knocking?

Go to Step 28

Go to Step 7

7
  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 8

Go to Step 9

8
  1. Coolant in the exhaust system creates a distinctive, burning coolant odor in the exhaust.
  2. 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 27

Go to Step 9

9

With the engine idling, inspect the coolant recovery system.

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

Go to Step 14

Go to Step 10

10

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

    • Coolant surge tank
    • Heater core
    • Radiator

Are any of the hoses, clamps or pipes leaking?

Go to Step 19

Go to Step 11

11

Visually inspect the following components:

    • The coolant pressure cap
    • The core plugs
    • The cylinder head gaskets
    • The engine block
    • The intake manifold
    • The radiator
    • The thermostat housing
    • The water pump

Are any of the listed components leaking?

Go to Step 19

Go to Step 12

12
  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 13

13

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

Does the coolant pressure cap hold pressure?

Go to Step 15

Go to Step 20

14

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

Does the coolant pressure cap hold pressure?

Go to Step 29

Go to Step 20

15

Inspect for the following conditions:

    • A coolant smell inside of the vehicle
    • Coolant in the HVAC module drain tube
    • Coolant on the vehicle floor covering near the HVAC module

Is coolant present?

Go to Step 21

Go to Step 16

16

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 17

Go to Step 18

17

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 27

Go to Step 18

18

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 22

Go to Step 30

19

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

Is the repair complete?

Go to Step 30

--

20

Replace the coolant pressure cap.

Is the repair complete?

Go to Step 30

--

21

Replace the heater core. Refer to Heater Core Replacement .

Is the repair complete?

Go to Step 30

--

22
  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 23

Go to Step 24

23
  1. Replace the radiator. Refer to Radiator Replacement .
  2. Service the automatic transmission. Refer to:
    3. •  Engine Coolant/Water in Transmission for the 5AT transmission
    •  or
    •  Engine Coolant/Water in Transmission for the 4T45-E transmission

Is the repair complete?

Go to Step 30

--

24

Install the cooler lines to the radiator.

Is the action complete?

Go to Step 30

--

25

Repair the engine no crank condition. Refer to:

    •  Engine Will Not Crank - Crankshaft Will Not Rotate for the 2.2L (L61) engine
    •  Engine Will Not Crank - Crankshaft Will Not Rotate for the 2.4L engine
    •  Engine Will Not Crank - Crankshaft Will Not Rotate for the 3.5L (L66) engine

Is the repair complete?

Go to Step 30

--

26

Repair the engine overheating condition. Refer to Engine Overheating .

Is the repair complete?

Go to Step 30

--

27

Repair the engine internal coolant leak. Refer to:

    •  Coolant in Combustion Chamber for the 2.2L (L61) engine
    •  Coolant in Combustion Chamber for the 2.4L engine
    •  Coolant in Combustion Chamber for the 3.5L (L66) engine

Is the repair complete?

Go to Step 30

--

28

Repair the engine knock. Refer to:

    •  Lower Engine Noise, Regardless of Engine Speed for the 2.2L (L61) engine
    •  Lower Engine Noise, Regardless of Engine Speed for the 2.4L engine
    •  Lower Engine Noise, Regardless of Engine Speed for the 3.5L (L66) engine

Is the repair complete?

Go to Step 30

--

29

Repair the combustion pressure in the cooling system problem. Refer to Cylinder Leakage Test .

Is the repair complete?

Go to Step 30

--

30

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 1