E91 annoying engine squeal unidentified. (sound included)

[liam-uua24]

Hi, Any ideas what this noise could be would be greatly appreciated.
Its sooo annoying and all fixes so far have well, not fixed it.
We get this noise/squeal at 2k rpm once engine is warm. Above and below these revs it's fine. Really annoyingly gives one last squeal on shut down. It's been like this for 3 years. It's not got better or worse. 2 garages have been unable to identify it. We have changed the belt, tensioner, water pump and A/C condenser. No difference. Car is serviced regularly now with 140k miles on clock. other than this it runs as good as new.

You can hear the noise in this video https://youtu.be/svJrRKuLx9Y

[Sardonicus]

And does the noise disappear when the belt is removed and run briefly ? it def sounds rotational to me

[bmwmike]

Care to give us a clue as to which engine?

[liam-uua24]

Hi, thanks for coming back.

Its 2.0d e91

From what the garages say the noise is not present when belt is off. However I can't help think if the engine has cooled enough while the belt being removed the noise may not sound... I do agree though, I'm sure its rotational...
What other possibilities are there to produce this sound?

[Eddieslofart]

Exhaust manifold gasket, had the same on my 335 d, bd took ages to find.

Try nipping the manifold nuts up.

[liam-uua24]

Thanks for the suggestion Eddieslofart. I will