The engine has a knocking sound when starting from COLD and went away completely after it warm up. You pro what is the problem?

I am positively sure these are not causing the problem because I checked and verified:

1. Removed serpentine belt, started the car and the engine knocking sound still there.

2. Replaced timing belt hydraulic tensioner and the sound still there.

Here is the knocking sound at cold start and after warmup

COLD START
https://youtube.com/shorts/Slnwc9KJEDY?si=4NZEDbKvkheo68HS

AFTER WARMUP
https://youtube.com/shorts/k4pVyicPU2Y?si=qdoJMsBqUgx88xKQ

 

Engine oil is too cold and too thick to be providing proper lubrication at initial start-up. Try switching to a lighter weight oil, see if it improves the noises.

What kind of ambient temps and weight oil are we talking about here?

 

Valvoline restores and protects 5w-30
oil level is fine
30F outside