Hi my freelander 4 cyl. 2004 1.8L had a hg replacement in 2005 under warrant. Never had a problem since then until recent sudden rise in temp gauge from slightly below half mark (where it always rest) to max hot with warning light & a second cooling fan kicking on. However, the engine water temperature would remain normal and if I switch off the car for just a minute and starts it again the gauge would return to normal readings & everything will be normal only ro recur suddenly in some future days. Any idea?