Notice: When adding coolant, use DEX-COOL® coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner-at 50 000 km (30,000 mi) or 24 months.

Notice: The 4.6L engine uses DEX-COOL™ and GM coolant supplement (sealant) P/N 3634621 specifically designed for use in aluminum engines. Failure to use the engine coolant supplement (sealant) and the approved coolant antifreeze could result in major engine damage. When refilling the cooling system, add three pellets of the engine coolant supplement sealant GM P/N 3634621 to lower the radiator hose.

1. Park the vehicle on a level surface.

Caution: With a pressurized cooling system, the coolant temperature in the radiator can be considerably higher than the boiling point of the solution at atmospheric pressure. Removal of the surge tank cap, while the cooling system is hot and under high pressure, causes the solution to boil instantaneously with explosive force. This will cause the solution to spew out over the engine, the fenders, and the person removing the cap. Serious bodily injury may result.

2. Remove the surge tank pressure cap. Refer to Cooling System .

2.1.	Clean the cap.

2.2.	Test the cap. Refer to Cooling System Leak Testing . Replace the cap if necessary.




3. Completely drain the cooling system by opening the drain cock at the bottom of the radiator. If the coolant is dirty, or if there are deposits in the radiator, flush the cooling system before refilling. Refer to Flushing .
4. Disconnect all the hoses from the surge tank.

4.1.	Remove the surge tank and pour out any fluid. Refer to Radiator Surge Tank .

4.2.	Clean the inside of the surge tank with soap and water.

4.3.	Flush the tank with clean water.

4.4.	Install the tank and hoses. Refer to Radiator Surge Tank .

Tools Required

GM approved Recycling System such as Pro Clean (Available in the GM Dealer Equipment Program)

Whenever the cooling system needs maintenance or repairs, remove and replace the coolant with qualified new or recycled coolant.

If you only drain the radiator, up to 50 percent of the used, contaminated coolant can remain in the cooling system.

Use any of the following methods in order to remove the coolant:

1. Close the radiator drain cock. Install the engine block drain plugs if these were removed.

Notice: Pure coolant can be added to raise the boiling point of the coolant, but too much will affect the freezing point. Do not use a solution stronger than 70 percent, as the freeze level rises rapidly after this point. Pure coolant will freeze at -22°C (-8°F).

2. Refill the cooling system.
3. Set the heater temperature to 32°C (90°F).
4. Allow the engine to continue idling until the radiator outlet hose becomes hot.
5. Cycle the engine speed up to 3000 RPM and back to idle 5 times.



6. Install the surge tank pressure cap. Align the arrows on the cap with the overflow hose.



7. Allow the engine to cool to the outside temperature. Then, check the level of the coolant in the surge tank. The coolant level should be at or above the surge tank landing (bottom) (1) in the inboard cavity (2) below the filler neck.