Anyone else experienced this:

Last 2 days it's been between 0 and 3c going to work in the morning.

After nearly 10 miles of driving the temp needle gets to 90c then stays there. Then I travel down a 3 mile hill and the needle starts to go back quite a bit below 90c

I've not noticed this before. When the temp has got to 90c it has always stayed bang on all the time.

Surely it can't be a thermostat as it gets to bang on 90c as normal and goes no further.

Driving steadily I get the same.

As you descend down the hill the load on the engine reduces which in turn affects the heat it generates.

The cold airflow through the engine bay will be enough for the temperature gauge to drop slightly.

If you were to park up in the cold with the heater on high and the engine ticking over then the temperature gauge may also drop as the heater is taking out more heat than the engine is generating.

It's a pretty steady run. 40-50 mph, very few roundabouts or lights.

On this particular hill the gradient is such that there is no load on the engine at all. At the top my mpg can be say 38 and by the time I get to the bottom it's about 46.

I get the same in the cold weather, my temperature gauge doesn't reach 90 until I've done more than 11miles which is a mixture of a/b roads

I thought mine may be faulty as it never moves away from 90 no matter how I drive it! Even towing my caravan, it stays right there, no movement... :wonder: