Hey

I just can't seem to get my s2 to stay cool. I have changed the thermostat, the rad (twice) just put a new one in last week. And I've changed the waterpump, and the sensor (both new from ford) It's got standard ic, and is running standard boost.

When i drive it at summer it stays above the "N" in normal and when I stop at a traffic light, it goes into the red in like 30 seconds.
When it's winter, like now, and snow and stuff, it stays just under the middle, but still climbs to just below the red at traffic lights.
But the strange thing is that when I start to drive again, it goes from the red and to the middle in 10 seconds..

Someone please help :