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Few Questions on Replacing a Piston With A bro2002 Grand Cherokeeken or Cracked Skirt

oldbill

NAXJA Forum User
Location
Michigan
2000 Cherokee 4.0L Engine 185000 miles.
In the processing of pulling my engine due to lower end noise. Thinking cracked or broken piston skirt. For any of you that have done this or any other mechanic out there. When doing this did you replace just the bad piston, or did you replace all of the pistons? If you only replaced the bad piston, did you replace all of the rings on all of the pistons or only on the replaced piston? Did you hone your cylinders? I've gotten conflicting information on whether or not you need to hone the cylinders. Being on fixed income I looking to spend the least amount of money that I have to, but don't want to cut corners that will rise back up to bite me. Any other concerns or issues I need to address?
Thanks,
Bill
 
super-duper cheap fix...
new piston with new rings and a quick hone of the cylinder. the new rings will require it for break-in. this is assuming the cylinder is not damaged or worn too badly.
i would only do this in an older secondary vehicle i didnt need to rely on just because you arent building-in any reliability. but it can work, just like replacing worn main bearings without a full rebuild.

better idea............. pull it all apart and re-ring all the cylinders, new main bearings, new piston if required, new oil pump and timing chain.
it would be better to squeeze this into your tight budget now, because if you half-ass it and it breaks again you will spend more $$ and time to do it all again.

make sure you get good measurements on the cylinder bore, top, bottom, middle.

there is a difference between cheap and inexpensive..
 
Hard to say what to do until you know what you are really looking at.

A broken skirt can result in a lot of damage in a short time, accelerating wear on that cylinder.

If the cylinder is not terrible, a new piston with a new ring set can be installed. A quick honing to break the glaze and away you go.
 
A few years back, my gf was driving our 96 and lost the water pump....she kept driving and managed to burn a thumb sized hole in one of the pistons and warp the head, they don't do too well without coolant.
Pulled the head and pan, pulled the pistons and rods expecting the worst.
I borrowed a bore gauge and precision straight edge from the machinist at work and measured the block.
To my surprise the bores were all in spec and not tapered as well as the deck still being level and this motor had over 180K on it at the time....these motors are bullet proof!
After some thought, I decided it was better to replace all six pistons instead of just the bad one to keep them all pretty close to the same weight and not have it run like a paint shaker!
So I picked up a complete engine kit for about $400(?) from www.flatlanderracing.com found a head at the jy and had it rebuilt, replaced the timing chain and oil pump, a quick hone and put it together (never pulled the motor) and it's still running strong, using no oil over 90K later!
Sorry for the long post but, what I'm getting at is you would have to pick up a matching piston from the dealer if you want it to be close to the right weight and you'd probably spend close to the price of a matched aftermarket set.
Hans
 
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