Background
I have replaced my engine after a little valve problem!! I bought a second hand 2.5 V6 BDG engine as a replacement for a BFC (seller did say it was a BFC!). However theengine is basically the same with an up-rated camshaft configuration.
Symptoms.
The car goes into limp mode at around 3,000 revs in fourth. If I let off the power which falls to 2600 –I can sometimes get it to accelerate past 3,000 revs. I also find the car has an effective maximum of 3,900 revs going up through the gears. When I change gear there is an intake noise.
I have a basic code reader which shows code 00575.
Solutions tried so far
A quick Google finds that this is a common problems with a vast amount solutions available. As a starterI referred to the Ross-tech codes sheet at:
00575 - Ross-Tech Wiki


1. Vacuum hoses incorrectly fitted or perished.

I have replaced all the 5.5mm and 3.5 mm hoses and I am pretty sure I have them correctly fitted (thanks to Crasher). The only hose I did not replace is the one that goes under the wing in the front which I believe goes to a vacuum reservoir.
BDGEGRvacsystem_zps020c43c2.jpg


2. N75 valve. I have replaced the N75 – no improvement
3. Clean turbo. I cleaned the turbo with Mr Muscle following instructions from this article – Mr Muscle Turbo Clean 2.5TDI | Audi-Sport.netno improvement. I was able to move the actuator lever up and down so all seemed well. The linked article has a similar engine to mine.

I feel the next steps are a new MAF sensor and then maybe a reconditioned turbo. However I seem to have good turbo boost at around 21 psi - see Torque picture below:

Torque.jpg

Hopefully I can sort this out without un-needed parts and expense!