It is not uncommon for the fault to be the expansion tank cap on the Rover 75, try a new cap, I have known several people replace theirs. Same engine, and Rover designed the Freelander.
Also, fan resistor, fan relay, and fan pcb faults are fairly common cooling fan failure causes.
Re gassing has about a 50%++ failure rate, especially a £30+ gas top up, which does diddly squat. Not long ago someone asked if they could compare mine (75) to theirs, mine was not that good, but I do not recall ever using the ATC, I open the windows. So I will not bother with it. Although in my case, my 75 being 14 years old, low mileage, sits in the garage from Nov till March, never turned on the ATC on low, it could well be gas, but why bother.
