Advice needed on 2007 Disc 3.

Hi all, I have just brought 2.7td V6 Land Rover Discovery 3 2007
I brought it as a project with faults. I have repaired all electrical faults, the only trouble is when the engine is running you get a knocking noise from the engine, 50 seconds after starting the car, the knocking get 35% quieter, and the engine has a oil leak from the back of the engine, it leaks roughly 1.5 pints every 30 mins, I am not sure if it is cam or big end fault. The car starts first time, every time.
All info and advice greatly received.
yours
Jason

I'd pull the sump off to make sure it's not got bottom end failure.
Unfortunately crankshaft, bearing and rod failure are quite common on this engine.

Try and pry the front pulley and see if there is any movement.