2009 Chevrolet Cobalt Owner's Manual - Page 287

Checking Coolant The vehicle must be on a level surface when checking the coolant level. If coolant is visible but the coolant level is not at or above the COLD FILL mark, add a 50/50 mixture of clean, drinkable water and DEX-COOL® coolant at the coolant surge tank, but be sure the cooling system is cool before this is done. The coolant level should be at the COLD FILL line. If it is not, you may have a leak in the cooling system. How to Add Coolant to the Surge Tank { 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. The coolant surge tank is located in the engine compartment on the driver's side of the vehicle. See Engine Compartment Overview on page 5-12 for more information on location. Check to see if coolant is visible in the coolant surge tank. If the coolant inside the coolant surge tank is boiling, do not do anything else until it cools down. Notice: This vehicle has a specific coolant fill procedure. Failure to follow this procedure could cause the engine to overheat and be severely damaged. 5-29