Engine temperature

[Dustysweeper]

Something I have been stumped with on this car (Citroën GP) is the engine temperature. It takes an age to get to a normal on idle. Normal on this seems to be just below half way, about 85°C. It'll heat up within 10 minutes when driving. However, at idle after a run, the temperature drops below 70°C and the heater becomes cooler.

Things I've done.... Changed the water pump and thermostat, changed, flushed and bled the coolant system. Same results.

Is this normal?

[MattBLancs]

Is it petrol or diesel? Diesels generate a tiny amount of heat when idling, no load.

However regardless of engine type, temperature dropping once it is warmed, certainly below 70°C, is not normal.

Potential the replacement thermostat is not working??

[CitroJim]

However regardless of engine type, temperature dropping once it is warmed, certainly below 70°C, is not normal.

No, definitely not normal... My Picasso, with a similar engine, is fully warm in a coupe of miles and very rapidly demists on a cold and frosty morning...

That said, I used to notice on all the diesel Xantias (including the HDi) I ran that on very cold days I'd see a very definite transient drop in the temperature gauge reading as the thermostat opened. The temperature would soon recover back to where it was before the 'stat opened. I never noticed any drop in heater output though...

If yours drops and stays there then I'm with Matt in suspecting the new thermostat. First check is to ensure it's exactly the right type for the engine.

[Dustysweeper]

However regardless of engine type, temperature dropping once it is warmed, certainly below 70°C, is not normal.

I ran that on very cold days I'd see a very definite transient drop in the temperature gauge reading as the thermostat opened. The temperature would soon recover back to where it was before the 'stat opened. I never noticed any drop in heater output though...

I see the temperature drop as the thermostat opens when I'm driving and it quickly recovers. The heating is hot as it should be at this point. That tells me the thermostat is working, the issue is after the journey and idling for 5 minutes, the temperature gauge steadily drops, as does the heat output.

I'll change the stat again once funds and time allow.

Thanks for the input...

[CitroJim]

Keep us posted Dusty