I'll have a look
At my car later. It annoys me as it don't sit straight, where as vw/audis that I'm used to just auto correct upto 90 do it's always in the middle once it's over about 70. Unless it overheats of course
There is the possibility that the thermostat is stuck partly open but the car would take a while to get up to temp.
The thermostat is very quick and simple to change and if you go to a motor factor like Mill Auto, Partco, Uni Part then it will be quite cheap too. In order as to not get any air locks in the system you will need to locate the bleed nipples on the cooling system and open them when prompted from below. You will also need a top-up header tank as pictured.
The rear bleed screw is very tight to reach and you will need to remove the airbox top, connecting pipe and intake sensor to reach it. The other is located on the airbox winter heater.
*DISCLAIMER - This procedure, if carried out is of responsibility of those carrying it out, not that of myself (the author) or peugeotforums.com*
1. Remove your top engine plastic cover.
2. locate the bleed nipples (see pics).
3. With a 10mm socket and bar undo the thermostat cover.
4. Remove the thermostat.
5. Replace with new thermostat but ensure the rubber seating ring is attached.
6. Replace thermostat housing and tighten down.
7. Put home made header tank into expansion bottle.
8. Add new water/coolant mix to half way up bottle.
9. Unscrew lower bleed nipple on airbox and allow cooland to drain through to it shows on the MAX line on the expansion bottle.
10. Close the bleed nipple.
11. Start the car and replace the expansion bottle cap. Allow the car to warm up to normal temp and shut the engine off.
12. Locate the bleed nipple at the back of the engine by reaching through between the battery and engine. (CAUTION ENGINE HOT!!) Remember that you need to remove the airbox top and intake sensor to reach through.
13. Unscrew the nipple by 2 turns and then screw back up tight.
14. Unscrew nipple on the thermostat housing by 2 turns and then tighten back up.
15. Replace the air intake sensor and airbox top then the engine cover.