VNT17 failure, but not really?

Hey so I recently purchased a 05 Passat tdi that wasn't building boost p0299. Following all the info I could find on the forums, ( smoke testing the intake, swapping the N75 with a known good one, data logging with VCDS, cleaning the whole EGR system, actuator works as it should, holding vacuum and moving how it should.) I had no ideas left.

I pulled the turbo ( which has little to no shaft play especially for one with 103,000 miles. I noticed that when you spin it by hand it would sometimes "catch".

Upon further inspection and disassembly I noticed it was contacting on the hot side between the wheel and heat shield/backing plate. Not metal to metal, but carbon deposits to the point it was actually slowing the turbo down to a stop. The entire vane system and ring was slightly dirty but nothing that required cleaning. (Did so anyway)

I have cleaned and reassembled and am going to reinstall in the car (waiting on parts). It seems to spin freely with no shaft play still.

Has anyone experienced this before?

Did you check the actuator to see if it holds vacuum?

oh yes, actuator holds all the vacuum, moves freely, whole 9 yards.

so I reinstalled the "cleaned" turbo. It was fine for a few pulls then fell on its face. Wont make boost. Ordered a new one and will dissect the current one again to look for failures. I'm guessing the bearing are worn enough to slow the spin, or it has more soot sucked into it.

Turbos don't work that way. Sounds like you probably have a vacuum leak somewhere or an n75 issue. You're definitely experiencing limp mode, just need to figure out why. If the bearing in the chra was that bad, the shaft would break in no time, and you would have lots of play.

so update,

installed a new turbo (verified turbo actuator and rod location per vacuum applied) , new n75, replaced all vacuum lines with extra material on "bends" so it wont pinch over, replaced all the the inter-cooler o rings and inter-cooler connectors, pressure tested intake system to 20 psi, removed and cleaned all buildup from intake manifold, resealed injectors with all new Bosch o rings, new fuel filter, new vac pump.
It runs a lot better but still throws the p0299 code. Car has new fuel in it from a trusted source.

you can hear/feel it make boost, then it dies off. Any ideas?

I have the vcds software, anything to dig through on there?

You may need to plumb in an actual vacuum gauge to see what the actuator/ n75 are receiving

that's not a bad idea, going to be tricky to watch that and the vcds commanded and actual at the same time. I know some people have mentioned they have removed/bypassed the n75, for the sake of testing purposes would that be beneficial?

so turns out the cam was worn to the point of not letting the valves open correctly. I didn't think it was worn that bad upon my inspection. A repeatable shop corrected me. Figured i would post the end result of my troubles.

Sad news, but not the end of the world.
Thanks for posting back solution!