Whining noise while in vacuum and boost [PAYING]

pysical

Sergeant
Jun 16, 2017
461
107
0
Ride
2009 335xi E90
I have a N54 with a speedtech bottom mount. After getting my car back together from bit of work I took it out for a drive. I didn't put the air filter in because I was just going for a quick test down the block. I did a test hit and then the boost just dumped without me letting off the pedal. It didn't make the "whoosh" sound like it would if you let off the pedal and the BOV releases it. So then I did it again but slowly built the boost. It did it two more times and grabbed a log of each, this was just for testing.

1. https://datazap.me/u/pysical/boost-cutting-out
2. https://datazap.me/u/pysical/still-dumping

After the 3rd one I noticed my turbo started to make a whine noise. This was a few months back and I don't remember all the details but I just know it started to whine when building boost, even when in vacuum.

Since that moment I have tried 2 different turbos, different wastegate, boosted tested multiple times, smoke tested multiple times. In fact, the head was removed from the car as well as all the hotside and cold side piping.

The noise is still there even if the outlet is disconnected, wastegate unplugged, and mac unplugged. I did stick a microphone in the engine back on the driver and the passenger and it is coming from the passenger side. I am stressing out over figuring out this noise and I am not sure where to look anymore.

The noise comes on while at about -2 vacuum and up into boost. It does it louder if I get into it harder versus slowly building into it. I have replaced all pcv and valve cover.

here is a sound of the noise: https://drive.google.com/file/d/1J1CCAsmZFwwOB52oor258w-F2ugg8eD5/view

At this point I am willing to pay anyone who can help me figure out the issue. 100$ via PP friends and family for whoever can put me in the direction to get it solved.
 
Last edited:

pysical

Sergeant
Jun 16, 2017
461
107
0
Ride
2009 335xi E90
Updated the post with more information. Paying someone who can help.
 

Asmo

Lurker
Aug 23, 2020
16
8
0
You are getting throttle closures, the wastegate is not opening most likely.