Ethylene glycol/water fill ratios have been established to ensure a minimum of 50 percent ethylene glycol. Ensure that all the engine block drains and air bleeds are utilized.

The cooling system capacity for the 3.4L is 10.4 liters (10.9 quarts). The cooling system capacity for the 3.8L is 9.6 liters (10.1 quarts). The quantities listed in the filling procedure include the additional quantity to displace the air remaining in the cooling system after a static refill. Unless the cooling system is completely drained, residual coolant reduces the amount of coolant required to fill the system. Always check the freeze point protection after filling a cooling system.

Using the correct fill ratio and the following procedures will ensure a minimum concentration of 50 percent ethylene glycol. Every five years or 240,000 km, (150,000 miles), whichever occurs first, the cooling system should be drained and filled using the following procedure.

Caution: As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the solution in the radiator without causing the solution to boil. Removal of the pressure cap while the engine is hot and pressure is high will cause the solution to boil instantaneously -- possibly with explosive force -- spewing the solution over the engine, fenders and the person removing the cap.

NOTICE: When adding coolant, it is important that you use GM Goodwrench DEX-COOL® or HAVOLINE® DEX-COOL® coolant. If Coolant other than DEX-COOL® or HAVOLINE® DEX-COOL® is added to the system the engine coolant will require change sooner; at 50 000 km (30,000 mi) or 24 months.

Important: This procedure significantly increases the amount of used coolant and diluted hazardous waste.

1. Park the vehicle on a level surface.
2. Remove and clean coolant recovery reservoir.
3. Remove the radiator cap when the engine is cool:

3.1.	Slowly rotating the cap counterclockwise to the detent. Do not press down while rotating pressure cap.

3.2.	Wait until any residual pressure (indicated by a hissing sound) is relieved.

3.3.	After all hissing stops, continue to rotate the cap counterclockwise.

Important: Store the used coolant in a used coolant holding tank. Submit the used coolant for recycling.

4. Place a drain pan under vehicle to collect all the drained coolant.

Important: For procedures requiring the cooling system to be partially drained, opening the radiator drain valve should provide sufficient draining and no further actions should be necessary.

5. Open the radiator drain valve located at the bottom of the radiator tank.



6. 3.4L - Open the air bleed vent (1) on the thermostat housing. The air bleed vent should be opened two to three turns.



7. 3.4L - Open the air bleed vent (1) on the thermostat bypass pipe. The air bleed vent should be opened two to three turns.



8. 3.8L - Open the air bleed vent (1) on the thermostat housing. The air bleed vent should be opened two to three turns.



9. 3.4L - Remove the engine block coolant drain plug from the engine left side.



10. 3.4L - Remove the engine block coolant drain plug from the engine right side.



11. 3.8L -- Remove both block drains (knock sensors).

Important: Dispose of used coolant in a proper fashion. Never pour used coolant down the drain. Ethylene glycol antifreeze is a very toxic chemical; disposing of it into the sewer system or ground water is both illegal and ecologically unsound!

12. Allow the coolant to drain completely.

Notice: DO NOT use cooling system seal tabs, or similar compounds, unless otherwise instructed. The use of cooling system seal tabs, or similar compounds, may restrict coolant flow through the passages of the cooling system or the engine components. Restricted coolant flow may cause engine overheating and/or damage to the cooling system or the engine components/assembly.

1. Close the radiator drain valve.



2. 3.8L -- Install both block drains (knock sensors).



3. 3.4L - Install the engine block coolant drain plug to the engine right side.



4. 3.4L - Install the engine block coolant drain plug to the engine left side.
5. Remove the coolant recovery reservoir and empty. Flush the reservoir with clean water. Install the coolant recovery reservoir. Refer to Coolant Recovery Reservoir Replacement .

Important: 

•	When filling the cooling system, add GM approved Ethylene Glycol Coolant DEX-COOL GM P/N 12346290.

•

If the cooling system is being refilled ONLY (no flush), a 50 percent ethylene glycol and 50 percent clean drinkable water mixture should be used to fill the system. Fill the system until the level of the 50/50 mixture has reached the base of the radiator neck. Wait two minutes. Check the level of the coolant mixture. Add a 50/50 ethylene glycol/water mixture as necessary to restore the coolant mixture level to the base of the radiator neck.

6. Slowly fill the cooling system through the radiator neck using the following procedure:

6.1.	If the coolant system has been flushed first add 100 percent ethylene glycol:

•	3.4L - 5.2 L (5.45 qt)

•	3.8L - 4.8 L (5.05 qt)

6.2.	Slowly add clean drinkable water to the system until the level of the coolant mixture has reached the base of the radiator neck.

6.3.	Wait for two minutes. Check the level of the coolant mixture. Add clean drinkable water if necessary to restore the coolant mixture level to the base of the radiator neck.

7. Install the radiator cap making certain the arrows line up with the overflow tube.



8. 3.8L - Close the air bleed valve (1) on the thermostat housing.




Important: DO NOT over-torque the air bleed valve. The air bleed valve is made out of brass.

9. 3.4L - Close the air bleed valve (1) on the thermostat bypass pipe.



10. 3.4L - Close the air bleed valve (1) on the thermostat housing.
11. Fill the coolant recovery reservoir to the COLD mark with of a 50/50 mixture of ethylene glycol and clean drinkable water.

Notice: The Low Coolant warning/indicator lamp may come on after this procedure. If after operating the vehicle so that the engine heats up and cools down three times, the Low Coolant warning/indicator lamp does not go out, or fails to come on at the ignition check, and the coolant is above the full cold mark in the reservoir, refer to Low Coolant Warning/Indicator Lamp in Electrical Diagnosis. If at any time the Temperature warning/indicator lamp comes on, immediate action is required. Turn OFF the engine and allow the vehicle to cool. Do not remove the coolant recovery reservoir cap at this time.

12. Inspect the freeze protection of the engine coolant after the engine heats up and cools down three times using a refractometer or a thermohydrometer to ensure proper freeze -37°C (-34°F) protection. Obtain the coolant mixture for the inspection from the base of the radiator neck, NOT from the coolant recovery reservoir.