Lovely machine. Must admit my 4.2 definitely thirsty but amazing cruiser. Got mine booked in for new thermostat as it over cools and new rubber hose that runs in the V below supercharger. Not leaking but can garantee it would when on motorway or something with family in car, don’t fancy being at hard shoulder with a 3 year old for hours waiting on Rac.
On my 4.0 Jag there's 2 solenoids that control how much water goes to the rad or the passenger / driver side of the climate control. The rubber seals fail allowing water ibto yhe solenoid which stops it moving properly. No idea if the Rangie is the same but it may not be the thermostat itself. Incidentally, the plastic thermostat housing on the Jag is a PITA and has an aluminium after-market kit available that is very good.