Caution: An electric fan under the hood can start up even when the engine is not running and can injure you. Keep hands, clothing and tools away from any underhood electric fan.

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: Do not add cold water to the cooling system with the engine at or above operating temperature. Adding cold water causes rapid cooling, resulting in possible engine damage.

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.

Notice: This 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 the lower radiator hose.

1. Open the radiator drain at the bottom of the radiator.
2. Completely drain the system.
3. If the coolant is dirty, or if there are deposits in the radiator, flush the cooling system before refilling. Refer to Flushing .
4. Remove the cooling system pressure cap.

4.1.	Clean, test, and replace the cap if needed.

4.2.	Clean the radiator/cooling system filler neck. Inspect the filler neck.

5. Disconnect the hoses from the surge tank. Remove the surge tank.
6. Pour out any fluid.
7. Clean the inside of the surge tank using soap and water.
8. Thoroughly flush the surge tank with clean water. Then drain the surge tank.
9. Install the surge tank. Connect the hose(s).

1. Close the radiator drain cock.

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: 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. In order to ensure sufficient engine cooling, freezing and corrosion protection, maintain the coolant protection level at -37°C (-34°F) or lower.
3. Mix DEX-COOL® and clean drinkable water to a 50/50 mixture.
4. Set the heater and A/C control to the highest setting.
5. Allow the engine to continue idling until the lower radiator to water pump hose becomes hot.
6. Cycle the engine speed up to about 3,000 RPM and back to idle 5 times.
7. After the air has been released, fill the radiator. Install the surge tank cap.
8. Allow the engine to cool to the outside temperature. Check the coolant level.