eng knocks

[lraffe1]

I have a 99 sd wreck with 175000 miles that came in with rusted oil pan and no clutch. I had another tech in shop install new clutch and oil pan. on test drive engine started to knock. I then cancalled cyl and noise lessons with cyl 7 inj unplugged. i then ran compression and all cyl around 350. i then removed and tested injs and found several bad including 7. i replaced injs and noise was still there. i then swapped 7 and 1 and noise still in 7. we pulled eng again and pulled bearing caps. the bearings showed signs of wear. i replaced bearings with crank in eng plastie gauge and are in spec. I installed engine and noise stil there. now engine is out and disassembled again took number 7 rod, piston, and right head to machinist and had checked okay. i then rechecked rod and main bearing clearences in spec. machinist also suggested maybe it has cracked crank. i have also checked new clutch and appears okay. i donot no if i missed something or not ayn suggestions would be greart appreciated.

[lmorris]

How exactly did they check the piston? I had one that had a knocking when hot. #8, so my first instinct was to put in the updated injector. Customer brought it back with same knock. Replaced the piston, assuming it was collapsed, and knock was fixed. Never had the piston actually inspected.

[lraffe1]

it knocks hot and cold, also changes with rpm amd load. piston was not miced. but rods were checked for startness while i waited. maybe piston is source. i was thinking of replacing rod and pistons, but would hate to put back in and still knock.