[bmwdiesel]

so this is what my charge air pressure (ladedruck in german) reads in actual vs desired values in INPA live data read out while stationary. I can press the throttle and it goes up, but then it falls lower than the desired value.
what would be the pointers for this?

desired (SOLL in german) is 1022 and actual (IST) is 845

I have just changed the vacuum lines (not all tho as I was short on sillicone hose and the rest seemed fine, but I will change it once I have will get the hose, but I am certain this here is a different issue than vacuum lines. perhaps the aluminium charging hose from intercooler or intercooler might be cracked? or the intake is leaking pressure? (I just changed the 6 squared orange gaskets that leaked some oil, but this lower actual stationary values are still the same )

[ranthum]

Check the seals on your intercooler piping.

[robnitro]

What altitude are you doing this at? At idle I see around 1020 bar and I'm at sea level

[bmwdiesel]

about 800 feet or 250 meters, but I dont think it makes any difference since car is regulating it itself, right? I guess. I also forgot to add that I had this issue before I was changing the vacuum hoses as well and I was hoping it will fix it, but it's the same lower charge pressure as before

[Roliz1231]

Hi. I had exactly the same issue, actual is so low because your small(HP) turbo is being bypassed at charge side, exhaust goes straight to big(LP) turbo which at this stage is not creating any boost and engine creates vacuum, in psi 1022 would be around 0 boost pressure, and 845 actually is already negativeboost(vacuum), that rise in boost what u can see when reving is when the big turbo starts doing its job. you didn't mention which lines have been replaced but might be you haven't changed the one for turbo changeover valve( thats that big canister u can see in front of your dpf, and nearly everyone incorrectly calls it a wastegate, making things confusing for someone with no knowledge in turbo systems and specially R2S. back in October when i spend 2weeks on forums looking for help and trying to get my head around what's exactly what, studied realoem and other diagrams and hours on YouTube, and only on 2d week it klicked for me and instead taking it to garage i took it upon doing myself. A bit of a side story there, probably because my first post 8)
Back where we left- even if u have replaced the vac line for turbo changeover actuator, it might be a bad pressure converter.
I changed both PC's and vac lines on turbo side, but unluckily one of the new PC was faulty, i didn't know which one, but testing for a vacleak one would hold it and other wouldn't let u create any vacuum with a hand pump, so i installed the one holding vac for turbo changeover and one from old ones which seemed to hold vac for a sec or 2 for wastegate and obviously that was the bad one(from new ones) probably it being stuck or electric fault but it was creating vacuum all the time, and because of that it would not switch over from small to big turbo...
that noise and smoke and probably my face when it happened on motorway....not sure what it was but if im correct that was a compressor choke.
Might be something else at fault, anyway i hope my experience might help others