VW Passat 1.9 TDI - Engine Sound/Roar

Good day.

My car has been making a howling noise since around October 2016. I've uploaded a video so you can hear exactly what it sounds like.

The diagnosis at the time was a turbocharger failure, so I had the turbo replaced. The only problem was that it didn't change the howling noise at all.

The Volkswagen dealership then told me that the new turbocharger was also broken and that I would have to replace it again.

I contacted the turbocharger manufacturer, and they said that the problem wasn't with the turbocharger itself, but with the car. They believe there must be a leak somewhere.

I have instructed that the following parts be replaced:

July 15: AGR valve (part number 038 131 501 AA).
Exhaust turbocharger (038 145 702 NX).
Oil supply line and oil return line.
All turbocharger boost hoses including seals.
all vacuum hoses.
Shock absorber (038 129 807).
Pressure sensor for turbocharger exhaust systems (1J0 906 627 A).
Exhaust gas recirculation pressure sensor (1J0 906 627).

I replaced these parts myself.
Solenoid valve (1J0 906 283 A)
Boost pressure sensor (038 906 051 C)
Check valve (046 905 291 A)

Unfortunately, none of this achieved the desired result. I also sent the old turbocharger in for inspection, but that didn't provide much information either, at least not for my garage. (Company correspondence and attached photos are included.)

I really don't know what else I can do. Maybe I should also mention that the car has had an *** chip tuning since 2002, which never caused any problems, and the tuning company has ruled out that it is related to the noise.

The garage maintains its opinion that the new turbo is broken, while the turbo manufacturer insists that the problem lies with the car itself.

I hope I haven't violated any rules this time, because I really need help.

Thank you in advance.

Okay, here's the translation:

Nad75