So my D2 has a cold start noise that has been around for a while. Goes away when temps get to operating (175-185). Sounds kind of like a oscillating knock. I have decent oil pressure - 52 cold start, between 12- 42 hot. Temps stay right at 180 +/-. Transmission shifts fine around town and at highway speeds (70-72 mph). I can't really isolate it but could be from the bellhousing. Any ideas?

And the small rag stuck in the inspection plate was to monitor a oil leak that has been fixed

You can hear it in the video attached.

 

Dodging a bullet here. Was concerned it was my flexplate. On further investigation, 90% sure its my drivers side catalytic converter rattling when cold. Took the inspection cover off and it's whisper quiet inside the bellhousing. Rover on...