i have a 1987 isuzu pup 1.9l motor with about 30,000 miles on major rebuild (local carquest shop). ratteling noise from front end of motor when its warm and revved up a bit. motor runs fine. noise goes away if you shut the motor off. rev it up and it starts making the noise again i pulled the valve cover to look at the timing chain and it looks ok to me. there is a small pin sticking out the tensioner shaft that i couldnt move. i dont know if that is normal. all the valve springs look ok. some of the rocker ( tappets)shaft nuts were loose and i tightened them up but it made no difference. i also loosened the altenator and air pump so they were not spinning as well the water pump and still made the noise. i can't find anything obvious. any advice would be appreciated

Optional Information:
1987 Isuzu pup (pick up) 1.9l

Already Tried:
i have loosened the altenator and air pump so that they were not spinning as well the water pump and it still made the ratteling noise. i removed the valve cover and tightened some of the rocker shaft fastners and looked at the stems and springs. found nothing obvious and it still makes the noise. please note the noise goes away if you shut the motor off until you rev up the motor.