VW Caddy weird noise

[andreibu]

Hello all.
I have seen a couple of posts with this specific sound, but there was no answer of how to get it fixed.
I am not a mechanic myself, I need your help, I've been to 2 mechanics and they can't figure it out.

I have a VW Caddy 1.6 TDI, 2012

This is the clip of the sound.
https://www.youtube.com/shorts/8vsUzx3Qqco

It's a weird humming sound, that is running from the moment I start the engine.
I've tried Air Con - on, or everything, steering, etc.
The sound only goes down in frequency when I accelerate, but it seems like it's struggling to do something when I do.

Can anybody help me diagnose the issue?

Thank you so much!

[STP]

Sounds to me like plastics drumming, I'd check the air filter pipework and battery tray. Bonnet up, touch stuff firmly till the noise goes away. Once you find something which quietens it down, tighten that.