Ok I know I have seen you guys post stuff about engine ticking/knocking but cant find straightforward info.

 

About 200k miles.

Engine is really quiet and smooth at idle, and normal driving rpm (some very light ticking comes and goes but sounds exactly like very minor HLA noise that I experience on all of my cars)   At exactly 4k rpm I get a ticking/knocking noise, but doesnt seem to affect power or smoothness (no misfire or vibration).   This seems to happen  when under load or not.  It is not intermittent, you can guarantee that it will happen right as you hit 4k.   Hydraulic lifters usually fail at lower rpm but higher rpm get "pumped up" by higher oil pressure right?   Rod knock is usually lower rpm or all rpm correct?   This is a manual so no flex plate... any ideas on what the most likely possibility is?   

i would pull a plug wire and see which one makes a difference with your noise. does the noise go away over 4000 rpm? how loud is it?

What year and engine?

 

I'd check the timing belt idlers and tensioner ASAP.