Boring thermostat question

[oli3442]

I have noticed over the last couple of days the coolant temp is sitting at in the low 80s instead of being in the high 90s as usual. Does anyone know if the ECU sets the thermostat lower purely based on a high exterior temperature?

2.0 bluehdi in a 2018 Dispatch.

Thanks

[albertosilvestro]

No, the ECU in your 2.0 BlueHDi Dispatch (2018) does not actively lower the thermostat’s target temperature just because the exterior temperature is high. The thermostat in modern diesel engines is an electro-mechanical device, but its primary job is to keep the coolant at the optimal temperature for efficiency and emissions, which for most BlueHDi engines is between 88°C and 95°C.

[oli3442]

Thanks for the reply. I guess something else must have upset it then, will monitor and see if I get any codes pop up.