2010 Buick Lucerne Owner's Manual - Page 331

Checking Coolant The vehicle must be on a level surface when checking the coolant level. 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 (4.6L Engine) on page 6‑27 or Engine Coolant (3.9L Engine) on page 6‑31 for more information. If no coolant is visible in the surge tank, add coolant as follows: How to Add Coolant to the Surge 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. { WARNING: An electric engine cooling fan under the hood can start up even when the engine is not running and can cause injury. Keep hands, clothing, and tools away from any underhood electric fan. 6-29