Just an update:

i have replaced the Oil Seperator and it fix two issues I was having, smoking at startup and when I put my foot down..

BUT, it is still under powered when the oil/engine has been at operating temperature for a while. As I said, when the oil is cold, it has all the power.

Now, I know for a fact I never bumped any connectors or hoses, and if I did, then I was in the wrong place when changing the oil. However, just to please the masses, I have spent 5 hours going over every plug/hose and they are all 100%.

So, has anyone got any idea what I should look at next? I still say it is the oil, and will be changing it to 5W30 in a few days, but I am still interested in people that actually know about diesels as to what it might be.

Anyone?