I filled my car with coolant after the light came on. I then drove for about three hours, checked it again and found the header tank completely empty. I inspected all the rubber hoses and found the leak to be coming from the highlighted part on this diagram:

As I'm sure you can see, the schematic is for an N/A cars, but I see little if any difference between the diagram and my engine.

Here's an incredibly **** picture of the hose in question, again with the problem area highlighted. Hard to photograph due to shape and location, sorry.



Can anyone provide me with a part number so I can find a replacement hose? Could anything else be causing this coolant loss?

Thank you.

 

Assuming you have a RHD car and assuming I've read the pages correctly, you need a MNA6724CC hose. Google that part number together with "Jaguar" and see what happens.

https://parts.jaguarlandroverclassic.../brand/jaguar/

Cheers
DD

 

That looks right, thanks.