Alright - gonna bump my old thread. Really appreciate all the help so far.
I've cleaned the injectors and replaced the nozzles, pop tested, etc and did a valve adjustment... Sporadic 'clack' and nailing still remains on cylinder number one, which is a little fishy to me, because I definitely got it to leave it on a previous injector swap. (maybe a crappy old injector helped hide it?)
My fear then is rod bearing on #1 as this seems to be the one commonly to go. Any other ideas for things for me to try? Mess with IP? Anyone in Atlanta willing to give a listen? Besides this noise, it seems to be running real well but I don't want to keep throwing money at it if it's gonna need a rebuild.
Here's the breakdown:
-cylinder #1 sporadic 'clack.' Sounds just like in this video in all parts.
https://www.youtube.com/watch?v=LIPKoSV9IuU
-knock doesn't leave on a diesel purge
-knock leaves when car is fully warmed (driven 15 min), returns after a couple minutes at idle
-nailing on cylinder #1 (you can hear/feel a little tap on every rotation)
-some white smoke at start; very little smoke besides this whether its idling or driving
-oil level good, doesn't seem to be burning/leaking much
-not a lot of blowby; oil cap nudges around a bit, but doesn't 'dance' when sitting loose