The Chevrolet Cobalt cooling system helps maintain proper engine temperature during normal operation. Your car's engine can be damaged if it is run without sufficient coolant, resulting in overheating conditions. Monitor the coolant levels at every oil change and any time the engine runs warmer than usual.
Park the Cobalt on level ground. Raise the hood and access the pressure cap from the driver side of the engine compartment. Make sure the engine is completely cooled before removing the cap.
Turn the pressure cap counterclockwise slightly. Stop and wait a few minutes if you hear a hiss. Press down on the cap and turn it counterclockwise to remove it.
Pour a blend of equal parts coolant and distilled water into the cooling system until the fluid is visible at the base of the filler neck, even with the "Cold fill" mark.
Replace the pressure cap on the coolant tank. Turn the cap clockwise until it is secure. Close the hood.
