I got an over heating problem with my 2003 Discovery. It did this about 2 months ago and i suspected thermostat so i changed it out and its doing the same thing again. it s over heating, both fans spinning, no coolant loss but the lower part of the house coming out of the rad into the thermostat is cold and soft the hoses coming out of the top of the thermostat are super hot and hard. thermostat stuck again?