Strange noise

Hi, for the past month or so my 1.6 hdi has developed a noise and i can't get my head around what it is. Its loud when the engine is cold and idling. Once you take it past 1000rpm it dissapears. Then once the engine is warm it isnt present on idle. However if you gently ease the accelerator you can hear it again but not over the 1000 mark as before. My first call was to slack off the serpentine belt and fire the engine up so all but the crank pulley would be stationary. Unfortunately the noise was still present ruling out any of those obvious ones. The noise almost sounds like a bad bearing being spun quickly. The noise is also not affected by gears or clutch pedal. Ive attached a video link you can hear the noise over the standard diesel engine sound.

https://youtu.be/LUd4Ejc-u1U

Well, it's loud.

Is the vacuum system working properly?


And is the performance ok?
Could it be a damaged inlet manifold?

Arfur Dent wrote: ↑Thu Feb 17, 2022 11:13 pm Well, it's loud.

Is the vacuum system working properly?


And is the performance ok?
Could it be a damaged inlet manifold?

I always thought the engine itself was loud but perfomance feels fine it is remapped from its original horsepower though but thats been like that for over a year now and still feels nippy.