nicdulvey

Who wants to take a guess at this dire sounding noise? Searched high and low, and after mowing through most youtube videos about different knocking, banging, rattling, hammering, ticking that don't just feature someone who likes to talk for 10 minutes, it's still an unknown. There are two videos here.

Only happens on cold start, and diminishes to nothing, the jeep drives and sounds as good as new once it's hot.

3 different oil filters, so no oil drain back issue caused by filter and causing a dry start. fresh 5-20 synthetic.
Noise is not rhythmic.
It is not coming directly from the catalytic converters, unless the noise is really travelling/radiating a long way from the source.

I have to describe it as actually object on object banging, but unable to rule out combustion with my limited abilities.

Timing change striking the cover, and then stopping once the tensioners get the full oil pressure and heat?

first video right after start: second video after calming down warming up a bit:

Sixty4x4

Any bits in the oil? An analysis would have helped a lot. My guess is timing chain even before reading your text. Any codes thrown? How many miles on it.

jsukey

I say pull that plastic engine cover off and get yourself a mechanics stethescope and see if you can't track down precisely where the noise is coming from. They can be had for less than $10 at Harbor Freight. That would definitely help narrow down the culprit.