post #1 of Old 06-18-2011, 08:15 PM Thread Starter
TomJeep177
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Cracked 2nd Piston

I have a 96 Jeep Sport 4x4 with the I6. My girlfriend drove it for about 5-10 miles with it over heating because the upper radiator hose was split. Anyways I was hoping I'd just have to take off the block and change the gasket, lo and behold the 2nd piston is missing a chunk. The wall doesn't looked scratched but I had to get the head machined. Now my question is how can I remove that piston without taking the rest of the engine out, and should I take the piston block to get checked out as well? The other pistons look fine.

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post #2 of Old 06-18-2011, 08:24 PM
leftlanetruckin
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Your terminology is a little confusing.
Do you mean you just pulled the head?
IF the cylinder walls indeed look good, then you just remove the oil pan, undo the bolts on the connecting rod, and push the piston out of the top of the block with the connecting rod attached to it. Be careful not to damage the cylinder walls though. I have little boots that fit over the bottom of the rod that stops it from scratching anything.
You will then get the new piston installed on the rod, install new piston rings, and slide it back down the cylinder using a piston ring compressor.

Martin

1998 XJ on 37's.JK Rubi axles with chromo shafts and ctm's, 4:1 transfer case, etc etc etc.
2003 Range Rover HSE, 4.4 Quad Cam.
1998 Range Rover with a 6.0 LSx
1994 YJ, 4.3/700R4/OME SOA, etc
Western Star 4900EX 4 axle.
4.3/700r4/new frame buildup (YJ)....
http://www.jeepforum.com/forum/f12/swap-offically-underway-324622/
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post #3 of Old 06-18-2011, 09:27 PM Thread Starter
TomJeep177
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So far I took off the valve cover, intake and exhaust manifold, and the head and saw that the piston was missing a chunk. Do you think I should also change the timing chain because it was overheated for so long?
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post #4 of Old 06-18-2011, 09:46 PM
leftlanetruckin
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Timing chain should be in the same condition it was in before the overheat.
For the piston to be missing a chunk due solely to a coolant issue is a little bit of a mystery though. Only time I have seen melted pistons is when either a piston cooler gives way, or there is a fuel/ignition issue. I guess it could be well and truly driven into the ground with no coolant and destroy a piston or two, but a few minutes?
If it was me and I saw that, the motor would be coming out in short order mate.
But you asked a question and I answered it. IF you want to replace just one piston, then you can do it perfectly well with the motor in place, assuming number 1 is at the front as you counted.

Martin

1998 XJ on 37's.JK Rubi axles with chromo shafts and ctm's, 4:1 transfer case, etc etc etc.
2003 Range Rover HSE, 4.4 Quad Cam.
1998 Range Rover with a 6.0 LSx
1994 YJ, 4.3/700R4/OME SOA, etc
Western Star 4900EX 4 axle.
4.3/700r4/new frame buildup (YJ)....
http://www.jeepforum.com/forum/showthread.php?t=324622
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post #5 of Old 06-18-2011, 11:34 PM Thread Starter
TomJeep177
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Well my idiot of a friend screwed up the spark plug order, so could it be from that? We tried starting it, it started hard and then stalled
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post #6 of Old 06-19-2011, 08:43 AM
leftlanetruckin
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The damaged piston from the wrong firing order? Highly doubt it myself.

Martin

1998 XJ on 37's.JK Rubi axles with chromo shafts and ctm's, 4:1 transfer case, etc etc etc.
2003 Range Rover HSE, 4.4 Quad Cam.
1998 Range Rover with a 6.0 LSx
1994 YJ, 4.3/700R4/OME SOA, etc
Western Star 4900EX 4 axle.
4.3/700r4/new frame buildup (YJ)....
http://www.jeepforum.com/forum/showthread.php?t=324622
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post #7 of Old 06-19-2011, 09:50 AM
chris142
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If it got so hot that it melted a piston I'm sure the others were damaged or weakened too. I'd rebuild or replace the whole engine.

If you put a piston in it and in 2 days another piston comes apart you will be doing it all over again.
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post #8 of Old 06-19-2011, 07:23 PM Thread Starter
TomJeep177
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The others don't even have carbon build up or scorching at all. Could I do some sort of test on them? before removing everything?
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post #9 of Old 06-19-2011, 07:30 PM
leftlanetruckin
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All you can do is remove them and inspect.
Looking at them from the top and saying they are fine is not the way to go in my book. As I said, it would be getting stripped down if that was my motor, but your call.
You can of course get 1 piston and slap it back together of funds are tight etc, but you will be holding your breath for the first 500 miles IMO.

Martin

1998 XJ on 37's.JK Rubi axles with chromo shafts and ctm's, 4:1 transfer case, etc etc etc.
2003 Range Rover HSE, 4.4 Quad Cam.
1998 Range Rover with a 6.0 LSx
1994 YJ, 4.3/700R4/OME SOA, etc
Western Star 4900EX 4 axle.
4.3/700r4/new frame buildup (YJ)....
http://www.jeepforum.com/forum/showthread.php?t=324622
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post #10 of Old 06-19-2011, 07:55 PM
herbiehind
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they can be inspected and put right back in if you like . i would at least look for cracks .don't mess up the rings . also look for seized rings as it got very hot . make sure they're all free and loose in the lands .
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post #11 of Old 06-21-2011, 06:37 AM Thread Starter
TomJeep177
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Any ideas how to get the oil pan of with the tire rod snd everything in the way?
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post #12 of Old 06-21-2011, 08:21 AM
chris142
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Quote:
Originally Posted by TomJeep177 View Post
Any ideas how to get the oil pan of with the tire rod snd everything in the way?
Start taking whatever is in the way out of the way.
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post #13 of Old 06-21-2011, 10:16 PM Thread Starter
TomJeep177
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Really wish I had a lift
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post #14 of Old 06-22-2011, 07:15 AM
leftlanetruckin
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Now you have me very concerned.
You are talking about tearing an engine apart and rebuilding it, but can't figure out how to remove the oil pan?

Martin

1998 XJ on 37's.JK Rubi axles with chromo shafts and ctm's, 4:1 transfer case, etc etc etc.
2003 Range Rover HSE, 4.4 Quad Cam.
1998 Range Rover with a 6.0 LSx
1994 YJ, 4.3/700R4/OME SOA, etc
Western Star 4900EX 4 axle.
4.3/700r4/new frame buildup (YJ)....
http://www.jeepforum.com/forum/showthread.php?t=324622
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post #15 of Old 06-24-2011, 09:08 AM Thread Starter
TomJeep177
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The the front differential is in the way, so its hard my hands up there
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