1998 Buick Century Owner's Manual - Page 282

Checking Coolant If this light comes on, it means you're low on engine coolant. Adding Coolant If you need more coolant, add the proper DEX-COOL@ coolant mixture at the coolant recovery tank, but be careful not to spill it. If the coolant recovery tank is completely empty, add coolant to the radiator. (See "Engine Overheating" in the Index.) When your engine is cold, thecoolant level should be at the COLD mark or a little higher. When your engine is warm, the level should be up to the HOT mark or a little higher. 6-22