2015 Buick LaCrosse Owner Manual - Page 274

Vehicle Care 10-21 reaches the mark pointed to on the front of the coolant surge tank. 5. Replace the cap tightly. 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. 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 { Caution 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 There is a coolant temperature gauge and a engine coolant temperature warning light on the instrument cluster that indicate an overheated engine condition. See Engine Coolant Temperature Gauge on page 5-13 and Engine Coolant Temperature Warning Light on page 5-22.