2007 Chevrolet Cobalt Owner's Manual - Page 302

{CAUTION: You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol, and it will burn if the engine parts are hot enough. Do not spill coolant on a hot engine. 1. You can remove the fill neck pressure cap when the intercooler system, including the upper intercooler hose, is no longer hot. Turn the pressure cap slowly counterclockwise about one-quarter of a turn. If you hear a hiss, wait for that to stop. This will allow any remaining pressure to be vented. 2. Then keep turning the pressure cap slowly, and remove it. 3. Add the proper DEX-COOL® coolant mixture to the fill neck, until there is coolant visible in the horizontal tube section of the fill neck. 4. With the fill neck pressure cap off, start the engine and let it run for at least 30 seconds. Watch out for the engine cooling fan. Turn the engine off. By this time, the coolant level inside the fill neck may be lower. If the level drops so that coolant is no longer visible in the horizontal tube section of the fill neck, add more of the DEX-COOL® coolant mixture to the fill neck until the level is again visible in the horizontal tube section. 5. Replace the intercooler system pressure cap. Be sure the pressure cap is hand-tight and fully seated. If the coolant is not at the proper level when the system cools down again, see your dealer. 302