New turbo gone bad already?

I recently purchased an '05 wagon knowingly that it had a bad turbo. It started fine, idled fine but tons of white/gray smoke pouring out and oil dripping out of exhaust. I removed the old turbo and sure enough on the exhaust side was all loose and wobbling big time. In the process I removed the EGR and cleaned it and tested to make sure coolant wasn't getting the vent pipe. However I did notice that the inside of the intake was full of black sludge. I cleaned it out the best I could while it was still mounted. I also noticed oil in the intercooler pipes and lines and cleaned that all out. I installed the new turbo and re-assembled. The massive smoking went away and seemed to run okay then when I gave it some throttle to test the performance, it lost power and check engine light came on. The code was for low boost. So I checked every hose and vac line. All good. Went ahead and put in a new MAF and Vaccum boost control switch. Cleared codes. Then the car runs perfect at idle and at lower speeds then I put my foot into it and it faults down into a safe mode. Then I notice oil still coming out of exhaust but actually even more than before and smokes a bit of gray smoke. Not like before at all but noticeable. I know if there is existing oil in the exhaust from the old broken turbo, you should take it out on the highway and burn it out. Problem is I cant get it up to highway speeds. Could the new turbo be bad already? Is it possible that some chunks of sludge from the intake got into the new turbo and broke it? Sure seems like the same symptoms. Before I tear it all down again , I thought maybe I could get some feed back. BTW this is my first TDI. I have owned MB diesels, Cummins, Detroit.

For kicks and giggles pull off the breather tube on the valve cover and then look for excess oil coming out while 4unning at idle. If it's just a fine mist move on. Couple things come to mind. First is a loose or leaky charge pipe connection. Next is a broken or loose vacuum hose to/from the n75 solenoid. Last but not least is a clogged exhaust from loads of oil, possibly the old turbo went bad because of running with too much back pressure?

I don't know how to test the n75 but i believe if its bad you'll get no power either. I know a broken vac hose going to it will eat all the power.

Could the catalytic converter be clogged?

Pull the airbox to turbo pipe and look at the compressor vanes. If they're damaged or there's evidence of the impeller striking the housing then the turbo is done. If there were debris from the old turbo in the intercooler pipes or intercooler they could have gotten pulled into the compressor when the turbo made boost and killed it. Sadly, it's pretty common.

VW procedure used to be to replace the intercooler and piping when replacing a turbo to avoid this. Depending on the nature of the original turbo failing, you can avoid this or remove the intercooling system and clean it thoroughly before running the car.

May be something else (plugged cat, boost hose off, vacuum system not operating properly) but I'd suggest you take a look at the turbo to see if it's OK.

My vote is for a charge air leak. A smoke machine is great for checking. The S-shaped hose off of the turbocharger could have gotten some metal punched through it.

Assuming the car is still an automatic, you can easily briefly brake torque it and listen for a hideous whooshing sound from a charge air leak.

Also check to make sure the vacuum system (which is dirt simple on the BHW, as it ONLY has the VNT actuator) is secure and routed properly, and the ying-yang valve up by the air cleaner is still good.

thank you for all the advice! I can't work on it till tomorrow. Going to take all the advice here and apply. I will get back to everyone after.

dubb, what brand replacement turbo you ended up getting?