My Discovery TDI300 started overheating yesterday when doing sensible motorway speed - hardly a hot day!!!
I had the heaters on full blast to try and warm the inside up but it was just blowing out cold air, and temp gauge got very high. I was about to pull over when all of a sudden warm air came out of hearters and temp gauge went straight down. Fine for rest of journey. Then a couple of hours later when driving somewhere else same thing happened. Any ideas?