Freelander temperature problem??

Hi All,
I hope you can help. I was out today in very cold weather doing around sixty on the open motorway and decided to put the heating up a couple on notches on the fan. When I did this the temperature gauge dropped to the bottom of the dial within a couple of minutes. The landy was going fine so I closed the heater and fan down and within a couple of minutes the temp, had come back up to normal. Is this a problem or was it just the weather conditions?
Thanks! Dick (Edinburgh)

Got enough anti freeze in there? Sounds like bottom of the Rad froze up.

What engine you got in your 99 plate FL1 Dick? I assume they did the 50th ann model in both petrol and Diesel. It does sound like a coolant flow restriction as Rocket says. If the gauge went down in temperature then it suggests the flow past the sensor stopped.. The gauge might have said low but the head temperature was probably anything but. Antifreeze strength a first port of call.

Check your water level.

Replace the thermostat?

sounds like faulty thermostat, does it take a long time to warm up

Thanks for all your help. Antifreeze seems to have done the trick but as advised I will keep an eye on the thermostat.
Cheers folks,
Dick.