How fix my caddillac

Did you chandelier thermostat it only two bolts if you boil water on stove and drop thermostat in and watch to see if it opens if not replace not exspecaly to fix

Before spending any more money on this vehicle have the coolant tested for combustion gases. If you have combustion gases in the coolant you have a blown head gasket and the vehicle is not worth fixing. All Northstar engines blow head gaskets sooner or later. So if you're having a cooling system problem, check that first. Hope that helps! Jim