I thought I would a bit more about the "culprit"... the cracked head!
Here is a pic midway through strip down. The cam carrier has been removed, note the residue of the sealant used between the head and the cam carrier
Now a close up of the injector pocket showing the crack circled in red.
You can also see some black witness marks inside the pocket showing that the injector had been in contact with the pocket just where the crack happened.
So the head went away for repair, the crack was quite deep, and a lot of welding was needed, after welding the pocket is machined out and the head is pressure tested, the injector clears the weld on top of the pocket.
I have a bit of cleaning up of the pocket to do!
A few before and after pics of the head and carrier. The sealant was in some of the small oil ways but that's how it came out of the factory and its been ok so far!
When you do a full strip down its good practice to keep everything in the same order that they were. These are the hydraulic lash adjusters, RAVE says "keep upright and in order"
"I" = Inlet, X=Exhaust, 1 - 5 Cylinders
Dirty bag/Clean bag
One of the valves, pre cleaning/lapping. Under a x20 mag the face was pretty pitted
Note: The leak was very easy to spot! Heres what I did:
Remove cam cover
Clean area around each pocket
Turn on ignition (remembering not to start it!)
Wait for the fuel pump to start
Use a torch and look at the area around each injector
Mine started weeping after just 1 minute I estimate the leak rate was very roughly 10ml/min, so that equates to 0.6 litres and hour, so it doesn't take long to fill your sump with diesel!