1997 Buick Regal Owner's Manual - Page 300

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 coolant recovery tank, but be the careful not to spill it. When your engine cold, the coolant level should be is at the COLD mark or a little When your engine higher. is warm, the level should up to theHOT mark or a be little higher. If the coolantrecovery tank is completely empty, add. coolant to the radiator. (See "Engine Overheating" in the Index.) 6-24