W221 coolant temp dropping

[wacomuk]

My wife's 2011 4.7 bi turbo s class came up with a fault. When scanned it said coolant temperature low.
Took the car for a spin and it stays around 80 around town. 90 idling and under 70 on the motorway.

To me this sounds like the thermostat is not regulating temperature properly. Or could it be something else?

If it's the thermostat is there anything that can be done to fix it or is it just a replacement part?

Is the thermostat electronically or mechanically controlled?

I struggled to find a thermostat on line for the 4.7 blue efficiency

 

[onefortheroad]

Should stay at 90 always. Dropping on motorways is a sure sign it opened early.

Id buy from a mb dealer .ask for discount.

 

[umblecumbuz]

First suspect is the 'stat.

 

[ajlsl600]

Have heard electronics now involved in thermostat now ? Good luck.

 

[Barnesautos]

Item 60 and electronically controlled

 

[mioba]

Stat all the way. Dealers for the part.