Weird turbo flutter and loss of power at high rpm

[Zeppe]

Not sure if this is the right forum but here goes:

I had a problem with my original turbo. Basically the actuator(? Not sure if its the right term. In Finland we call it turbo clock but dont believe its the right term in english) on the turbo, where the shaft thing is connected was stuck, and I only got boost in high rpms and was very sluggish in low rpms.
I replaced the turbo and immediately heard this weirdly strong woosh sound when building boost, and some flutter when letting go of the throttle. Still I took it for a spin and sure enough: no power in high rpms. Checked everything and replaced the MAF.
After not finding anything I took to a mechanic and sure enough the new turbo was bad.
Welp. I got the turbo changed again at a mechanic. Deleted the egr system by blugging the end of the exhaust manifold and coding it out of the picture. Now I’d say it pulls better in the lower rpms but still has no power in the high rpms and has this weird flutter sound when letting go. I called another mechanic about the issue and they told me its possible my original turbo had a bigger turbine/flaps or something along the lines but it still doesnt explain the fluttering sound. Plus now its like really slow in the high rpms. I could understand it being a bit slower but it just doesnt really pull at all. Im talking several second 80-100kmh if not over 10. When i change the gear it will move normally and accelerate 80-100kmh in just a couple seconds or so.
Now i checked for fault codes and it threw a code of ”oil temperature sende” when driving at about 2100rpms. When i slowed down it didnt come back again. Also it doesnt throw the code when accelerating. Only when sitting at around that 2100rpm mark at 110kmh.
I also got a code for solenoid 1 (n88) but dont believe that would affect anything that has to do with acceleration/lack of power. Correct me if im wrong.
Any ideas of what could be the problem? N75 valve or? Im honestly stuck with this cause as a student im really tight on money and am trying to sell the car. Thank you in advance.

 

[Zeppe]

Alright so a little update. I changed the n75 solenoid valve. Didnt help. Went to a mechanic (again) and they told me theres an issue with overboost which for some reason my reader read the code as ”oil temperature sender” idk honestly. Well anyway they told me it could be possible that my dpf is full of carbon buildup and i should get that checked out. Turns out that while it was pretty clogged, it didnt really affect anything and am still having same problems. They found it weird that my other mechanic figured the dpf could be to blame since the code apparently couldnt in any sircumstances even mean that the dpf is clogged… Welp now im waiting for a bosch MAP I ordered and will replace the original one. If that doesnt help I guess I’ll have to double check my intake manifold and intercooler etc if theyre clogged.. another weird thing: while I got my dpf cleaned they notified me about the turbo making a lot of noise which i told them i had noticed and found weird, but wasnt really too put out since it was a new turbo installed by a professional. They told me its very weird that my turbo makes that kinda noise AND they told me there was play in the bearingsI asked them if the overboosting could have broken the turbo 2 different times in different ways and they told me its vert very unlikely since the computer activates limp mode everytime overboost happens. Idfk.. am I just very unlycky with the turbos im getting or is there something logical that could cause all this?? I need answers as Im losing my damn mind over this. Will update when i get my new MAP installed. I guess I’ll have to see myself

 

[Zeppe]

Right, I replaced the MAP sensor: no change. Im wondering if the anti-fludder valve could have stuck mid-way and is causing my problems? I dont know, but I’ll check it out once i have the time alongside with the intake manifold. After all that is done, if it doesnt get any better, I have no idea anymore. Everything is checked/replaced/cleaned and still doesnt work. I also checked in with the guy who replaced my turbo and he said the vnt is set from the factory so i believe its all good from that end. Will update once there is something to update.

 

[Zeppe]

SOLVED: I took the car to a mechanic since i couldnt figure the problem out myself. pparently you need to code the n75 to work for your exact car for it to work properly, that wasnt my main problem tho. They told me I had mixed the connectors up on my vnt and breather temperature sensor tho i believe they meant n75 and the breather sensor since its almost impossible to mix the earlier together.. anyway now the car works wonders. Maybe somebode somewhere in the future can learn from my mistakes. Or not.