1994 Buick Regal Owner's Manual - Page 226

Adding Coolant To Check Coolant When your engine is cold, the coolant level should be at "COLD" or a little higher. When your engine is warm, the level should be up to "HOT" or a little higher. If this light comes on, it means you're low on engine coolant. LOW COOLANT The coolant recovery tank is located at the left of the engine compartment. To Add Coolant If you need more coolant, add the proper mix at the coolant recovery tank. If the coolant recovery tank is completely empty, add coolant to the radiator. (See "Engine Overheating" in the Index.) 224