What is this noise?

[AlexNJ89]

[youtube]https://youtube.com/shorts/Eb_OrhxgiFM[/youtube]

It's an R53 1.6 Cooper S.

Seems to be coming from the left side of the engine where the aux belt is.

Thanks!

[E-bmw]

Could be many things unfortunately, you need to get in there to stand a chance of telling really.

Supercharger
Supercharger bearing
Pulley on drive belt
Drive belt loose
Alternator

Any other symptoms?

Does it go with revs, get louder, get faster?

[AlexNJ89]

E-bmw said:

Could be many things unfortunately, you need to get in there to stand a chance of telling really.

Supercharger
Supercharger bearing
Pulley on drive belt
Drive belt loose
Alternator

Any other symptoms?

Does it go with revs, get louder, get faster?

Fair yeah.

It appears almost exactly 30 seconds after starting the car, like the ECU is triggering something that rattles.

After some forum reading, I think it might be the Purge valve