[gm62]

Hello!

Before diving in,
I've got a '14 M sport auto, 95k miles.

Things done:
-Malone stage 1 tune (previous owner)
-vrsf charge pipe (previous owner)
-vrsf catless downpipe (me)
-ARM boost pipe (me)

Recent replacements:
-ofhg
-oil pan gasket
-valve cover
-transmission pan

Backstory-
Car ran perfectly fine with all things installed/maintenance done.
About 2 months after downpipe was installed, I started hearing a crazy whistle under near WOT. youtube short of sound >>https://youtube.com/shorts/To-jCd_cyJE

This is when I replaced the boost pipe, as the sound came from that side of the car and when I checked, the stock one was looser than....we won't go there. Didn't make the sound go away.
Took the car to a reputable european shop in the area and had them pressure/smoke test the car. They couldn't find any leaks anywhere. Said the car is "perfectly fine". Had a tech ride along while I did a pull and he just giggled at me and said "thats a happy turbo if I've ever heard one!"
But I've never heard this noise before and it happened out of the blue.
My mom has an f10 n55 with similar mods and it doesn't make this sound.

Fast forward a few weeks, unplugged the battery to remove the steering wheel (put new leather on it - OO WEE ).
Had it disconnected for about 6-8 hours, plugged it back in and went to bed.
The next morning I tried starting it for work and it immediately died. Tried again, and after starting it ran like ass. Threw drivetrain malfunction and idled really high, misfired when idle dropped. Was kind of bouncing around everywhere. Shut it off, assumed the throttle was pissed that the car lost power, left the ignition on for a bit and started it again. No more error and drove fine. Stayed that way for a week, but I kept finding valvetronic codes (in info more often than memory. only in memory whenever malfunction happened.
-1340A2, Valvetronic servomotor: overload (not present but stored)
-133B04, Valvetronic sysyem: no adjustment possible (not present but stored)

next round of clearing/driving:
-102A22, Air mass meter, working range: Air mass too high
-135704, Valvtronic system: Warning threshold for control deviation exceeded
-135502, Valvetronic servomotor: warning threshold overload protection exceeded
-135704, Valvetronic System: Warning threshold for control deviation exceeded
-135706, Valvetronic System: Lower stop learned.
cleared, restarted:
-102A22, Air mass meter, working range: Air mass too high
-135704, Valvetronic System: Warning threshold for control deviation exceeded

Drove fine with the occasional rough cold start, problems came back when it got cold af outside on cold start.
Malfunction comes back on cold start but goes away when restarting car.
New codes that pop up (a few times now, the only ones I'm getting):
131501: Vanos, inlet, cold start: not adjustable
120408: Boost pressure control: Shutdown as a follow-up reaction

once warmed up, the car drives perfectly fine. Sometimes when put into park, the idle will jump up. But that's it. Whistling noise still present.


The question/reasoning:
Is that whistling normal? My gut says it's not. If not, wtf is it? I'm at a loss.
Does it tie into the running issues? Why did they only start when the battery was unhooked? If it doesn't tie in, what are these cold start issues? The engine doesn't make weird noises and runs fine after initial startup.
I've scoured the forums for similar threads- and I've found some- but nothing that helps me even begin to understand what it is that I need to fix.
Maybe valvetronic but not valvetronic, vanos but not actually, vaccuum/boost leak but test was fine? The more I think/research into it, the less I know where to start.

[gm62]

Update:

Still haven't located the whistling sound. Will probably put in a separate post.

Idle issues and codes: Unplugged the pedal tuner I forgot the car had. No more idle issues, no more drivetrain warning, no more codes. 2 cold starts and long drives without issue, though it's been a lot warmer this week than the last few.
Going to see if it stays alright, and if so put the pedal tuner back in and see if it goes back to having issues again (it was fine with the pedal tuner before unplugging the battery. Something about that made the tuner and the car disagree with each other.)

[scubajim]

The whistling sounds like a wind noise. Air blowing across something that is whistling, not a turbo noise. IMO. The smoke test eliminated the possible leak. Is it just WOT or will it occur at higher speeds?