Turbocharger Problem? Oil buildup? Other?

[MiniDeLux]

I have a 2009 Clubman Diesel with approx 100,000km on the clock. Car has had the clutch done (new flywheel included) and has had the turbo replaced under warranty due to leakage of exhaust gasses. After the turbo was replaced I had some issues with the intake hose sliding off the turbo because the crankcase vents oil vapour between the MAF and turbo intake and contaminates the intake piping. I replaced the orange seal for the intake pipe and cleaned everything with brake cleaner and now that hose isn't going anywhere.

Due to the loose intake hose, the car had been suffering from unmetered air entering after the MAF, but when I cleaned up and reattached the intake hose I figured everything was copacetic - that is, until I drove another 2009 Clubman D. That car has power, especially down low in 1st and 2nd gear. By comparison mine accelerates like a wet noodle. Clearly something is still not right - although fixing the intake pipe did help somewhat.

By process of elimination, I have concluded that the problem must exist on the compression side of the turbo because the air filter is new, the MAF sensor is ok and the intake pipe is brand-spanking new and firmly sealed and attached. The clutch is NOT slipping.

Has anyone got any suggestions on where I should be looking next? Turbo is fine, no play in the shaft and it's a brand new unit. Car idles fine, no black smoke or anything else coming out the back, but I'm seriously lacking acceleration and power in the low end. The car is not throwing any codes.

Any suggestions would be welcome!

Thanks!

[MiniDeLux]

Okay, the car was serviced today. They replaced the air filter and a small section of tubing with a hole in it. The loss of power problem remains. Basically, I can jam the pedal to the floor and the car slowly accelerates but there's none of the 240 N.m (260N.m with overboost) pull that there used to be. There are no error codes being thrown.

I'm at a loss. Can anyone suggest where to start next?

[The Nun]

Almost as if theres some sort of timing issue?

[MiniDeLux]

The car idles absolutely fine and runs smooth. There is just no power on acceleration. It's gotta be connected to the charge air circuit I think, only I can't pinpoint it. Everytime I think they've found a problem and they repair it, it doesn't resolve it.