Oil Cooler Leak

[Dead Eye]

Why will you loose all the oil?

Drain it into a clean container replace the O ring behind the oil cooler and put the oil back in!

I did not think of that :| Wow, now I feel like a complete moron

Is it leaking at the bottom of that thin metal pipe? Try undoing the bolt and check if there is a crush washer either side of the metal line. So there should be one between the engine and the metal line and then one between the metal line and the head of the bolt. Hope that makes sense. Also if it is leaking around those washers you could try just getting two new copper washers and that might solve the problem.

Nope, it is literally leaking from the join between the oil cooler and the sump. Got a bit confused by the rest of your message unfortunately