Tapping noise 2007 Volvo 670 cummins

So I'm at the ta in Albuquerque,nm and I had a bad exhaust leak after I hit a deer a few nights ago it fell right before I hit it, so it was on its side, but any way tore my exhaust tubing up between manifold and muffler, I have also had this tappin noise for about the same amount of time, checked egr, not it. A guy thought it was a turbo last night now they don't know what it is, heading to a Volvo dealership as soon as they finish here, but what could this noise be? Tuck kinda idles rough, but it's done that since I've owned it, it used to only do it cold, now it seems like even warm it rough idles. But the noise is a tapping intermentent noise right side of motor, mechanic here at ta say it sounds like a valve needs adjusted, possibly needs overhead??

 

Just bought the truck two months ago I've only on my third run with it, was, they pulled the oil pan and the mains are bad and I have that spring piston ring from several Pistons in the pan, soooo I'm having an inframe done

 

Well I'm getting ready to have my truck towed to someone else, these people are greedy as hell, they got pissed bc I ordered my own parts for ALOT cheaper than they want to sell me the parts, and then when I cut the labor through making them reuse some parts they tell me I can take my truck somewhere else