Vnt ring in upside down? Turbo weirdness

Long story short.. did tb on wife's 06 bew tdi automatic, that went fine no problem. Torsion. Value of 1.5 when warm. But Nipple broke off turbo actuator, replaced with a used on that seemed to check out ok with mity vac. Car seems strained at idle and would bog when revving it and sputter. It was barely driveable and catch some hints of boost but almost nothing.

realized vnt was sticky, so took turbo off vnt17 cleaned vanes. Now when at idle, n75 to turbo line shows 23hg, 1150 mbar boost. Could rev up to 3k+ with no sputtering. Vac system holds a steady 27. Egr is deleted so vac lines are super simple. Vwmikel tuned, no smart actuator. Car will barely get up to 15mph, no boost, kinda smoky. No turbo at all. Put in a brand new actuator, same thing. Tried a brand new OEM n75.. nothing. Forgot to out the n75 line back on the actuator at some point and the car ran great!! Thought I had it fixed.
Until I realized I forgot to connect that, put it back, and back to nothing and the strained idle. Took a quick ride with boost gauge and actuator disconnected, and drove great, no more noticeable smoke than how it used to run, boosts up to 25+ psi. Looking quickly at vaglog, boost is a bit laggy behind specified but great power.
What gives? I thought with actuator disconnected I would get no boost and car would run like crap.
Is it possible I somehow put the vnt ring back in upside down such that it would act like a naturally spooling turbo based on fueling?? I'm totally confused here. Don't really want to pull turbo off again if it would be pointless. Turbo innards looked great.

I feel like I'm in the turbo version of Seinfeld's bizarro world. Up is down and don is up..

So I took the turbo off again, realize it was still a bit sticky, didn't clean it as well as I thought. Took the hot side apart this time and really cleaned it up. Everything moving totally smoothly and all looks to be in great shape. Also, the vnt17 ring appears to be totally symmetrical and can only fit one way so that doesn't seem to be the issue. Back on car and hooked up as normal. Good idle, revs up well in neutral again (makes some boost maybe up to 1500 mbar). Try and drive and it tries to make some boost, but it's sputtering and shaky, smoky, maybe 10psi boost at best when it catches. No power and hear some metallic clinking like it's the turbo.

Vacuum at idle is 23ish. Checked whole vac system no leaks at all. Did basic boost pipe testing with my air compressor and block offs. No discernible leaks. When I rev in neutral, vacuum goes evenly down to 15 or so. In gear, it barely goes down at all, actually even goes up to 25ish! I try manually bleeding off vacuum with my mityvac in hand down to 15 and doesn't help.

New air filter too, tried 2 other known working n75s. Tried disconnecting line to air box. Unplugging maf.. etc.

Yet I can disconnect the line to the vane actuator on turbo and plug the out barb on the n75. And the car will rev freely up to 30psi if nearly floor it (didn't want to go beyond that but I was close to flooring it) and drives awesome. No visible smoke, great power, boost drops to less than 3 if i let up on the go pedal. My boost gauge is a little shaky sometimes. But no big spikes in boost I can srr. Cruising steady I see the normal boost of 2-5. Basically drives like a really nice tuned bew.

I'm totally confused. I thought I understood how this works and have never been stumped like this. Am I missing something totally obvious? I can't believe the turbo is bad if it can boost and drive so well.

At this point I have no idea what to do. For kicks I disconnected the actuator line on my mk3 with a 17/22 and it also boosts up ok, maybe to 15psi. Drives kinda like a stock but smoky tdi. My wife's bew feels like a finely tuned machine lol.. at my wits end

Nobody? Am I totally confused... I must be misunderstanding something obvious? Safe to drive like this? Lol... Will take some boost logs later. I thought with vac line to the actuator car would run like crap and no boost, but it's the opposite

Actually bypassing the n75 by putting your vac line on the actuator closed down on the vanes so it should build boost easily. I’d be careful with the WOT, you have no boost control, so you could spike that thing pretty hard , unless you run a boost control.

I’m actually having a similar issue so I was hoping someone would respond. To daily it I’ve been putting my mityvac on the ATM side of the n75, so almost as if it’s got full vacuum to the actuator. I was hoping I would see a vacuum drop. It reacts slightly differently than if I put my vacuum line straight to the actuator. If I let it stay open to atmosphere (gas fuel filter) I will get a drop off in boost and emp at different random times. Wonder what plugging the ATM up and I get more consistent boost means.

It feels as if we got some vacuum leak but like you said, new n75, all the lines test as fine and the pump is pushing 23 in/hg just fine all the time while in gear.

It's an automatic not sure if that has anything to do with it. In neutral, I see good steady 23hg, can rev it and see it drop smoothly down to 15 maybe around 2000 rpm. Put car in gear and go, and vacuum barely drops as I rev. Even goes up a bit to 25hg. Makes no sense... Actuator on turbo moves easily and freely. I also removed the little check valve and have n75 vented directly to ATM, no difference

How does it respond if you plug the ATM side ? Got boost ?

Confusion may be that the vacuum at max actually is no boost, vacuum off full boost.
This is based on the fact that when you start the engine the actuator moves all the way.
At this point it may need adjusted. Adjust the double nut on the rod so it just starts to move at 3.5 to 5.0 "/Hg.

Right. I get that. Actuator is all the way down (no boost) when car is idling. I set the length of the actuator to be exactly the same as the old broken one I took off. And it does start to move around 3-5hg with mityvac

That's all good. Could the vacuum tube to the brake booster be leaking?

Well I'm going bonkers. While fiddling around some more, with the actuator vac line disconnected from the n75, I manually pressed it down on the turbo and it seems to *make* boost. While doing that I realized a plug on a blockoff plate on the intake manifold was completely missing!! Boost hissing when the actuator is pushed down?? Not sure how I missed that but so I was like AHA!! problem solved!! Plugged it and hooked everything up as normal fully expecting that this was the culprit. Same problem! Except this time the car actually died out too while trying to "boost". Vacuum actually goes UP to almost 25 when I try and drive.

I swear the turbo must be working backwards but the 2nd time putting it back together i could only see one way the vnt ring fits.. totally miffed and wish I had taken a stinkin pic. Really does not seem to have any vacuum leaks, tested it at the nipple on the large check valve..

Car idles like it's straining when hooked up right, but actuator disconnected sounds good. And driving like that boost is great lol...

Somehow possible I did something wrong with the timing belt? Can't see how....

What about a bad map sensor?

What turbo and what actuator are presently on the car? Is this the original BW turbo and actuator? What replacement actuator did you install; BW or Garrett?

Garret vnt17. Has been on the car for 150k or so, with one cleaning prior to this maybe 70k ago (wife doesnt drive it hard enough). Car has 235k on it just did the 2nd tb. Replacement actuator is the standard one for a Garret vnt for alh. Smart actuator is tuned out so no need for the pricy bew one. Vacuum pulls actuator in as it should.

I once had an ALH problem where I zip tied the turbo actuator vac hose too tightly and periodically it choked off the vac when the hose warmed up.

forgot i never updated this. so my understanding of how the actuator works at the time was somewhat faulty. the problem turned out to be the set screw was either missing or falling out, i don't remember, but that was the main culprit - so it was trying to boost way too much. got the set screw in right (roughly showing 3 full threads iirc) and all was well. previously i had thought the actuator was out all the way at idle (no boost) and as you drive, it pulls in vacuum to make more boost or less boost. but in fact, at idle it's full vacuum and pulled in, and it bleeds off vacuum to lessen boost as the ecu desires. if the set screw is missing, it's boosting *too* much and you can hear the strained idle and car jerks and craps out when you drive it so far out of alignment from what it wants.

i was reminded of this because couple months ago turbo was acting up again, but since it's not being driven much i ignored it, until then it was really bad. quick check in vcds and i had a suspicion the set screw fell out (could hear whistling at idle, boost showing 1120ish mbar at idle). indeed it had, and miraculously was still hanging around on the bottom of the skidplate. went to put it back in, and it kept turning. threads gone and rusted out. also noticed the vanes were sticking again! argh! wife doesn't drive it hard enough, and it also hasn't been driven as much due to working from home. so off the turbo came again, this time got it extra clean and grinded off a slight amount of bubbling rustiness that was causing a couple vanes to stick when the collar was screwed in tight - i believe this was the main reason for the sticking, not so much the soot, moves very freely now. re-tapped the set screw hole for a 6mm and all is well again... except the crappy flexpipe on the stainless 2.5" downpipe is toast (temporarily put in an old alh downpipe), as are the parking brake cables - thanks to the crapy vw metal wire hangers that ruin the sheathing and cause the whole thing to rust out. i do my own hangers now that are much nicer (even just a ziptie with some heater hose protection is better), but had never bothered to do that on this car since the cables sheathing was already crap.

oh and yes, the vnt ring goes in only one way

Love the follow up. This is sure to help someone!

Thanx for the update. Don't know what set screw you are referring to. I did not see one on my replacement VNT 17 smart actuator.

the set screw is on the steel body of cartridge. it determines the maximum amount the actuator can be pulled in.

with that being said, i'm actually not 100% sure - at idle, should the vacuum be pulling it right up to the set screw? i believe yes?