2010 Chevrolet Impala Owner's Manual - Page 299

If the coolant in the recovery tank is constantly low, you should have a dealer/retailer service department inspect the vehicle for leaks. 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. Engine Overheating The vehicle has several indicators to warn of engine overheating. There is a coolant temperature gage and a warning light on the instrument panel that indicate an overheated engine condition. See Engine Coolant Temperature Gage on page 4-30 Engine Coolant Temperature Gage and Engine Coolant Temperature Warning Light on page 4-30 Engine Coolant Temperature Warning Light. 4. Then fill the coolant recovery tank to the COLD FILL line. 5. Install the coolant recovery tank cap and the pressure cap. After a day or two of driving, when the engine is cold, check the coolant level in the recovery tank. If it is low, refill it to the COLD FILL line. 6-29