Espace 2.2DCI engine fault pressurised crank

help! I have a pressurised crank. I have replaced the rocker cover/inlet manifold with a new one. I have replaced the turbo. I have compression tested three of the cylinders which are comparable in pressure but the fourth glow plug is stuck. I think I will have to strip the top down to get it out as it now feels cross threaded. However this is an aside issue. I am struggling to think what it could now be. The most common cause is the inlet manifold but this is brand new. I have installed it very carefully with correct torque settings and sealant in the correct places. The coolant is clean without contamination. Also when you try and rev the engine its slow to increase the revs but when the turbo kicks in it splutters and dies. its undrivable.

I believe the pressurised crank is starving the engine of oil as the lifters sound like a bag of spanners. Please see video below.

https://youtu.be/CO3RZS7ABt0

any help appreciated

Espace 2.2DCI engine fault pressurised crank