Sounds like bag of nails on start up when cold

Hello,

The rattling noise is due to not having oil at the top of the engine, especially at cold starts.
As the engine warms up the oil circulates, and the noise stops.
First you want to make sure you have sufficient oil in the engine, as low oil can create this noise when cold.

This could be due to a weak oil pump, and it is taking longer than usual to buildup oil pressure and have sufficient flow.
This noise is quite common with these vehicles.

https://www.2carpros.com/articles/rattle-noise

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.