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piston slap


NAXJA Forum User
has anyone here experienced piston slap on engine start up? I had some piston slap when it got colder here in charlotte nc and i was coming to werk one day and low and behold engine noise!!! it broke a piston skirt on number 2 cyloinder from where the oil control ring land is down -completely took out the skirt-03 4.0 25,ooo miles-fixed it and now 1500 milkes later i get a rattling sound on startup.it come sin at 3k or so then after 5 min of running no more noise!!! it is a 5 spped nv3550-only noise when driving if i rev it by itself-no noise!!! is this common????piston slap again????or do i go chevy 5.3 v8?????
the slappy piston may have worn the cylinder bore out of true, now any replacement piston will slap, at least until heat expands it.

On my recently deceased 4.0, my number one piston slapped to the point of cracking, like yours the crack was in the piston skirt.
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There's a tendency in the forward cylinders to go sour. At least in the HO engines.
Even a stroker can go slappy. Maybe more so with the longer throw on the crank. The side-to-side forces are greater on the piston with the longer crank throw.
But reboring the cylinders can straighten out a slightly misaligned bore. Bottom line is, a stroker is more fun per mile, no matter how long it lasts.
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.060 is considered risky, its the last overbore you'll do with that block. Too little wall thickness between cylinder bores.

A 5.3 engine would really hop up the crawling torque, but damn thats a ton of refitting. Everything goes from the transfer case forward.
Youll be driving an experiment...might be a blast.
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i know a 5.3 has been on my mind fer 2 years now-i werk as a mechanic and it was at a chev dealer for the pastr 3 years nott one 5.3 engine issue at all plus they shure can make nthe tahoes an suberbs have lots of spped an torque man that would be sweet in an xj 295 hp stock-plus you can get them at car parts .com for like 400 bucks fer an 2001 or so- all day long.i dunno maybe just .030 over bore and new pistons .i just really dont trust it any more.my 4.0 days are limited now-2500 fer a good strocker or less to put in a reliable chevy 5.3 hmmm........................:badpc: