it's a noise.
no rod would go that far.
pull the iSC, connector. and with feathering foot (idle will be INop)
drive.
noise gone.
try a $3 harbor freigth stethoscope. and listen to all objects on motor.
my bets:
problem is outside motor.
or
TBELT was ignored, at 60k 120k, 180k. and is beating the crap out of casing.
or
the valve rocker rail locking screws were put in with out loctite or staking.
they came loose and you hear the noise.
you put in valve seals at rebuild? of heat. 8 seals.
The ISC can , and for sure go bad at 200k,
some get so loose inside it is a wreck.
and just pounds away.
on one car ,we had to unbolt it and plug up the holes because
it beat away from the vacuum pulses. (for testing)
how steady is vacuum. like a rock? 19 inchs at idle.
also that top , air tube to ISC, pinch it , (need busy throttle foot)
and this will kill idle air. does noise stop.?
http://www.kick-fix.com/TBI-1w.jpg
see label. IaC fresh air.
