Diesel knock/miss fire....

Hi guys.
When drivin my car last night, my engine decided to make a god awful knock, it's now underpowered. If it were a petrol I would be checking for spark etc.....but I ain't used to oil burning things.
Exhaust has been a little noise from the turbo down pipe for a little while if that helps.

Well after extensive investigation plus about 100 phone calls to nrgserv, diagnostics is complete.
I worked out it was cylinder 4 from the good old fashioned manifold test (run engine for a min and feel each exhaust manifold, 1,2 and 3 were hot to the touch, 4 however was barely warm), i knew fuel was getting there (cracked off the fuel line to cylinder 4 and it was being delivered, but to be safe i checked the pressure was roughly the same on cylinder 3 also).
So, f***ed injector (neil said not hugely likely), bust head gasket, bent pushrod, broken rocker all possibilities we were hoping for rather than f***ed piston/rings etc.....

So.....off with the rocker cover.....


See what's missing?



So after adjusting it (unfortunately no feeler gauges here), jobs a good one


Please note, i am joking and please never use spanners as feeler gauges. Parts are on order (rocker adjuster, valve cover/cap and new rocker gasket). Pushrod and valve move freely and my neighbour (who i found out today is the garage foreman at local LR dealership said its relitavely common on 200's).

Thanks to nrgserv and mr LR lol

So where are the missing bits?

Its quite hard to see, pics 2 and 3 the rocker at the back has the threaded bit with the button on missing

I could see the bits that are missing I meant where have they gone too , as this could be come an issue later.
The tappet end should not be able to pass the pushrods nor the valve cap so probably lying against one of them.

Aaah I should learn to read properly, actually I never considered the missing bits!