We have  a 2017 180 TDi---- It takes about 6 miles for the temp guage to move off "Cold" then another several more miles to reach "normal" (we do get heat during this time).  Our old 2008  petrol  S Max  used to reach operating temperature in a mile or so-  Is there a thermostat problem or is this normal on the new turbo dieisels??

8 hours ago, stephanies said:

It takes about 6 miles for the temp guage to move off "Cold" then another several more miles to reach "normal" (we do get heat during this time).  Our old 2008  petrol  S Max  used to reach operating temperature in a mile or so-  Is there a thermostat problem or is this normal on the new turbo dieisels??

In this weather, 6 miles or more to get to temperature sounds normal to me, for a diesel. They are a lot more efficient than petrol engines, so waste a lot less heat into the cooling jacket. Downside of that is a long warm up time, especially in low speed (urban) running with the cabin heater on.

If you stop after 5 miles or so, with the temperature gauge still low, and carefully feel the big hose from the thermostat to the radiator, then that should still be cold. If quite warm, then the thermostat could be sticking open.

But my 1.8TCDI takes over 5 miles to get to working temperature, and that is on 60 limit roads, with some hills. So it is probably normal.

Seems about right my Mondeo used to be the same and my current C-Max 1.5 Tdci does the same.

That seems ok.

If it was a over-cooling issue (thermostat stuck open) then I would expect the gauge to drop when driving above 30mph (more airflow to the radiator).

If it doesn't and stays stuck in the middle all seems just fine.

Our 2006 2l petrol takes a little while to get warm. Was your petrol a 2.5?