Missing Sensor by Coolant?
 

Hey guys,

I just bought a 2012 Mini Coupe S a few weeks ago and today I changed my oil just to be on the safe side. While I was in the area I notice that there was a open double prong port, that I assume to be a coolant sensor right below the intake pipe.

I have been researching as much as I can but I can't pin point what it is or why its empty. The car is running perfectly fine and if I wasn't changing the oil I probably wouldn't have noticed otherwise.

Any input would be helpful. Thanks!