Is it heater core

Hello, a pressure test of your cooling system is essential to determine where the coolant is leaking out of so that you may make a successful repair without continuing to guess at various components along the way. Remember that as you add coolant you may be exposing your cooling system to air pockets which can make the system look empty once they purge. When contents are under pressure, they will expose the source of a leak. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops