1995 Buick Riviera Owner's Manual - Page 231

Adding Coolant NOTICE: If you usean improper coolant mix, your engine could overheat and be badly damaged. The repair cost wouldn't be covered your by warranty. Too much water in the mix can freeze and crack the engine, radiator, heater core and other parts. The engine coolant recovery tank is located on the driver's side of the engine compartment. To Check Coolant When your engine is cold, the coolant level should be at FULL COLD or a little higher. When your engine is warm, the level should be up to FULL HOT or a little higher. 6-22