How to replace thermostat on 2003 aviator

Instructional information must be obtained via repair manuals that can be purchased or obtained via technicians near you. I would strongly suggest professional assistance. Thermostat is a guess and maybe a good one, but maybe not. A professional would have a diagnostic tool that can measure actual engine temperature as well as important data such as cooling fan operation and commanding. www.repairpal.com/repair-shops

This is a tough replacement, very involved. I am not a mechanic, but very mechanically inclined. to get the proper instruction a nd phots to guide you, you would need to look up the cooing for the 2003 Mach1 mustang. Trust me, every book you find will start of "aviator" but soon changed to Navigator or Explorer. No, they are extremely different, I have never seen a configuration in all my life. where is it? the thermostat resides in a combination housing, oil filter bypass mount and Power steering pump bracket found on the driver's side of the motor, newt the front, ( bumper side) of the block. I found it necessary to remove the inner fender splash shield. When you DO replace it, replace it with a 180 degree of lower thermostat.