Help Tacoma 2006

Hey guys, I just rebuilded my 2006 tacoma V6 4L, took it for few rides, about 1000kms and just this morning when I started it up it had a little knock, changed the oil, nothing in it so i doubt it would be a snub bearing, thinking that it might have something to do with the timing, but why would it only pop up after 1000kms? Would like to have some of your ideas before I start investigating,
Head redone by machine shop specialist
Cylinders bored 0.50
Crank turned and everyting
New pistons oversizes and new bearing all over, fitting why the news specs of the crank

 

Is it a rod knock or piston slap from a poorly done rebuild? Since you said the cylinders were bored I'm gonna say you might have piston slap. Or the timing chains are loose and slapping the cover. There's so many variables here.

 

It’s not a rod knock and couldnt be a piston slap, might have something to do with the chain tensionner

 

Ended up being a exhaust leak from the flange right after the manifold!