'93 tracker, USA, 1.6 8v 4wd, 207,000mi engine "hammers"

[billb4515]

Purchased car 5 years ago at 147,000 miles. It had just had a valve job by a reputable machine shop. When going down the road with even a bit of a load on it, engine sounds like a rod is about to let go. Guy at Hawk Suzuki said to "run it". I have been. Now have 207,000 miles on it and it sounds the same. Heard another Tracker from Canada this winter that had only 60,000 miles on it and it sounded the same. The noise is driving me crazy. (er)

No metal in oil or filter. It's not valve clatter. The valves are adjusted properly. Timing is set at 8 degrees advance. Using 87 octane gas. It is using about a quart of oil in 500-600 miles and is ready for a rebuild. Any suggestions as to what it might be?

Bill

[jtgh]

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.