Saturday after about 30 mins driving my temp gauge went almost to red, i stopped and turned off the engine, i turned it back on and gauge was back to normal, been ok over the weekend then this morning after 5 mins driving did the same again almost to red, again stopped on engine off/on and it was back to normal.

What could the problem be?

I have a 2005 range sport

One of many things, but first i would check my water level If its low, top it up, then i would check my oil filler cap and see if its full of white sludge, if it is... Have you been driving a lot of short journeys? Ie stop starts, or does it get regular long runs? Sounds like it could be a faulty temp sensor, worst case scenario, head gasket failure, or cracked head

As ady said check the basics first.

It could be a faulty sensor or actual problem Mike

2014 Facelift Discovery

Temperature sensors are a fairly common occurence. And its the easiest/cheapest place to start