Hello, I was wondering if anyone could know what was causing the sound from my engine. I was doing some testing and I had let the engine run for a little bit and then I heard this dingin sound , I shut the engine off straight away so I did some inspection because it sounded something was hitting my fan but found nothing untoward. I started it very briefly and the sound was there again. Anyway I took a video, the sound happens in the last few seconds.
Thanks to you all.

https://www.youtube.com/watch?v=xAXFdzje9Lc