On top of eng. in front of oil filter is a plastic unit that has separated so as fast as i fill the water it runs out. the 10mm hose from the header tank and the very top (approx 30-40mm) main radiator hose run to it. Does anyone know what this part is called ro order one. I am a long way from the closest Jag dealer. Photos attached but sits under.
Any help in identifying would be be greatly appreciated,, thankyou

View from engine top, sits underneath

The unit itself showing 10mm header tank hose connected, can see just behind has separated.

Down through top in front of filter

 

I used to have a 2010 XFS with the same engine as yours but I can't figure out from your pics which exact part you are talking about, even after looking through the Workshop Manual.
If you don't have it already get yourself a copy of the 2010-2011 XFS Workshop Manual from my Dropbox here: https://www.dropbox.com/s/lghw4v21pw...op3LD.pdf?dl=0
Don't worry that it is for the XFS, the engine and all parts of it in your car are identical.
Then if you can come back with the name of the part you need and the page it is shown in the Workshop Manual and I will be able to find the part number for you.

 

Thanks will have to try it on my computer, doesnt load well on my phone im hoping to trace it through a diagram that names it as its the only thing that small header tank hose goes to