2012 Chevrolet Impala Owner's Manual - Page 245

Vehicle Care 4. With the coolant surge tank cap off, start the engine and let it run until the upper radiator hose starts getting hot. Watch out for the engine cooling fans. By this time, the coolant level inside the coolant surge tank may be lower. If the level is lower, add more of the proper mixture to the coolant surge tank until the level reaches the mark pointed to on the front of the coolant surge tank. 5. Replace the cap. Be sure the cap is hand-tight and fully seated. Notice: If the pressure cap is not tightly installed, coolant loss and possible engine damage may occur. Be sure the cap is properly and tightly secured. 10-15 indicate an overheated engine condition. See Engine Coolant Temperature Gauge on page 5‑12 and Engine Coolant Temperature Warning Light on page 5‑20 for more information. If the decision is made not to lift the hood when this warning appears, get service help right away. See Roadside Assistance Program on page 13‑5. If the decision is made to lift the hood, make sure the vehicle is parked on a level surface. Then check to see if the engine cooling fans are running. If the engine is overheating, the fans should be running. If not, do not continue to run the engine and have the vehicle serviced. Notice: Engine damage from running the engine without coolant is not covered by the warranty. The coolant surge tank pressure cap can be removed when the cooling system, including the surge tank pressure cap and upper radiator hose, is no longer hot. 1. Turn the pressure cap slowly counterclockwise. If a hiss is heard, wait for that to stop. A hiss means there is still some pressure left. 2. Keep turning the cap and remove it. 3. Fill the coolant surge tank with the proper mixture to the mark pointed to on the front of the coolant surge tank. Engine Overheating There is a coolant temperature gauge and a engine coolant temperature warning light on the instrument panel cluster that