Nasty cooling system
 

So i have a leak in my radiator on my 2001 Taurus 3.0L, and i decided to replace the t-stat anyway while im at it for ****s and giggles well i go to pull it out and see that inside of the block looks nasty and is all orange and so is the t-stat, the t-stat looks like rust, but the inside looks like orange paint

Attachment 2632
Attachment 2633

Why don't you try this.
Flush the system the best you can with a garden hose refill it with the correct type and concentration of Prestone. You can add a cooling system corrosion inhibitor if you like , but the new coolant should have everything you need in it. Have done this a few times on similiar vehicles and never had any further problems. Depending on the mileage , Don't forget to flush out the heater core (In Florida), Yes there too!