Hello
Engine has been making this noise (rattling/knocking) occasionally for a few weeks now after a cold start. It goes away after warming up a little.
Ps: It is quite cold here right now about -12C and oil has a slight gasoline smell to it.
Hope i formatted the video and thread correctly, its my first post.

What weight oil are you using?

I'm using semi synthetic 10w-40.

Reading material - one of many.

Depending on your location and weather extremes, you may want to re-evaluate the oil weight your using.

10w-40 should be fine in almost any kind of climate so I don't think it would cause that kind of noise. Is the noise coming from inside the engine or around it?

Its coming from the engine but its warmer now and most of the sound is gone on cold start. Brought it to my friend and he thinks the timing chain is probably failing. :/

How many miles are on your W124 and do you have any kind of past service records for it to see what servicing might've been previously done? MB timing chains are typically replaced at 100,000 miles.

Pull the oil filler cap off . now is that noise louder with the cap off ?