Strange sound after oil change

[JavierCL]

Hi.

My (gasoline) engine was fine, sent it to a mechanic and now there is a mental sound on the 1st minute of start up and only in cold, he put 0w20, after 6 days i changed it to 5w30 and the engine sound is the same, but the 0w20 had a lot of metal particles, you can see them here:

https://www.youtube.com/shorts/6BiAd5sWXAg

This is the metallic sound.
https://youtube.com/shorts/kOW6Yc0SMHI

The same metallic sound sounds at engine stop as well:
https://www.youtube.com/shorts/dND-bu7Rrn4

Also after releasing the gas, there sound comes up a little bit:
https://www.youtube.com/shorts/wslGOv6XKpw


The mechanic is blaming the problem to the low cost fuel. But it was perfect before he touched the car.

Thanks for your help, Javier.