2011 Buick Lucern Owner's Manual - Page 319

Checking Coolant The vehicle must be on a level surface when checking the coolant level. The coolant level should be at or above the FULL COLD mark when the engine is cold. The coolant level should be above the FULL COLD mark under normal operating conditions. If it is not, you may have a leak in the cooling system. Check to see if coolant is visible in the coolant recovery tank. If the coolant inside the coolant recovery tank is boiling, do not do anything else until it cools down. If coolant is visible but the coolant level is not at or above the FULL COLD mark, add a 50/50 mixture of clean, drinkable water and DEX-COOL coolant at the coolant recovery tank, but be sure the cooling system is cool before this is done. See Engine Coolant for more information. How to Add Coolant to the Recovery Tank { WARNING: 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. Notice: This vehicle has a specific coolant fill procedure. Failure to follow this procedure could cause the engine to overheat and be severely damaged. If coolant is needed, add the proper DEX-COOL coolant mixture at the coolant recovery tank. 6-33