Okay, if the thermostat is like new I have had them be bad right out of the box], then this is going to be an issue with your vehicle's water pump going, or has gone out. Underneath the water pump is a little hole called the weep hole. It will have coolant leaking from it if it has gone bad. This is done to keep the coolant from leaking down to the bearing and causing it to seize which would shred your serpentine belt causing other components like your vehicle's power steering pump, A/C, etc., to all fail as well. Here is a link explaining how to change a water pump below:
Please go through this guide and get back to us with how everything turns out.
Tuesday, November 5th, 2019 AT 4:54 PM