Preface, I’m not a mechanic, not even close. So any help would be greatly appreciated.

I have ‘12 Countryman All4 S- all stock.
A couple days ago on my way home my Engine temp light came on. I pulled over and found that I had no coolant in my reservoir. Long story short I found a sensor that I thought/think is my ECT sensor half way out, allowing all the coolant to escape. I wired it in place and was able to make it home. However I have 2 questions.
1. All of my google searching of an ECT sensor does not bring up this sensor, and is not in the same location. However when I took the part in to NAPA, they matched it to a BMW coolant sensor.
2. This was not plugged in to anything. The attached picture is just how I found it. No loose wires in the area.
So, what is this sensor? And should it be connected to something?

Any help would be greatly appreciated.

[img]blob:https://www.northamericanmotoring.com/01e15eae-ac02-40e1-a78a-5ae5e28e3d58[/img]

 

There was a mid cycle revision, and that sensor was included on some cars, but isn’t connected to anything. The actual coolant temp sensor is in the thermostat housing. Follow that yellow and white wire harness to find the actual coolant temp sensor.

 

Great, thanks for the help.

 

To followup, if that elbow/sensor is the source of the leak, you have a couple of options. Some have had luck with a plastic cement or weld product. Otherwise, there's a revised hose that eliminates the elbow altogether. You'll find many references in old posts.