Engine Blown - We Can Rebuild, We Have The Technology, Just Not the $$$

CherokeeHelpMe · 01-23-2008, 10:49 PM

hi all, thanks in advance for any help provided.
well i got a call from the girlfriend the other day with a question of why the motor just blew up and how far she could get. answer to the question, not far, which i found out after towing it home, working in the driveway in below freezing temps and finally clearing enough space in the carage to work and feel my hands....drum roll.... a snapped rod which sent the piston up and into the spark plugs and valves in cylinders 4 & 6, i think.
i've gotten the rockers and pushrods out and i'm waiting for some money before i remove the head, replace the valves and hope that the cylinder walls aren't marred, or the cam broken, or god kows what else.
there was so much sludge in the engine that there wasn't any liquid oil, which i love, because an engine rebuild is so much cheaper than an oil change on schedule, right???

anywhoo, i wanted to hear from those of you who have been through a 4.0L rebuild and have any guidance. i know in theory what to do but i haven't done a rebuild on this engine and i don't want to screw it up.
are there any things i should look out for or maybe add or do to the rebuild so i can get a better than stock engine without having to drop a ton of cash? i want this to be my project over the next coming months and i wanto to do it right and do it once.
any pictures would be extremely helpful, and thanks again for any help.

Kruzin · 01-23-2008, 11:12 PM

Can you say STROKER?

Bore it out .030 over, use 258 (4.2L) crank and rods, and end up with a 4.7L powerhouse.
I know when my 4.0 eventually dies, thats what I hope to do with it.

**5.9 ANDY** · 01-23-2008, 11:31 PM

ok you only need 4 things to fix this

1. stroker.
2. high performace rebuild
3. bore .030 over
4. and least importiant.... lots of $$.

seriously, you can do a stock rebuild, or just get a new motor... but it would still be uber cool to do a stroker.

**Katesdad** · 01-24-2008, 08:01 AM

Whats the deal with all the sludge? How many miles are on the motor? Any interest in buying one from the for sale section? If I tore the top off an engine and saw a bunch of sludge and had a broken rod Id completely tear it down...which costs nothing. But I do understand that its darn cold in the drive.

Yes there are tons of good links on the net. Google search 4.7 stroker and 4.0 rebuild. Remember the 4.0 was in about every jeep so dont limit yourself to the grand forum. Id really like to know the miles and why all the sludge was in there.

CrazyDrivinJoe · 01-24-2008, 10:06 AM

i had my number 1 cylinder rod break on me i got a free 4.0 and just swapped it out and re used the good things from my engine... I would also think that if you broke 2 rods unless they disinigrated like my rod did they might have not hurt the walls... i personally would want to get it honed or bored out smooth tho... or if you live close i can give you my old engine with only one blown cylinder but the block is still in pretty good condition. you need to completely rebuild it tho because it has been outside un covered in rain and snow since march lol

**Vestjam** · 01-24-2008, 09:24 PM

I went through this a year ago on my 95ZJ. Short story: Bad #6 cylinder on original 4.0L (cracked wall...water in oil... not fun). Picked up a used motor for $100. Dropped pan on 'used' motor and found most of #3 piston in bottom of pan (too far of a drive to take it back). Tore down entire motor. Machined head/block and honed cylinders. Polished crack. Engine rebuild kit... $600 later, I had rebuilt motor. My first. It's still running.

Could have saved some money on a good used motor, but I enjoyed putting the new 'used' one back together and I have a better feel on how everything works.

Get a GOOD factory service manual for the JEEP. It will cover entire engine rebuild and other things. Well worth the money!...

Good luck.

driabyor · 01-24-2008, 09:48 PM

sludge = pennzoil
poor maintenance
for an engine check a salvage, kiiji or craig list. heck you may even be able to pick up a whole jeep that's been totaled cheap

I have 310,000 mile on my 5.2 ... so if I would have not change the oil. EVER. I would have saved almost 2 grand.. But I don't think my engine would have lasted this long.

impuresoul2k3 · 01-25-2008, 09:16 AM

Quote:

Originally Posted by Vestjam

I went through this a year ago on my 95ZJ. Short story: Bad #6 cylinder on original 4.0L (cracked wall...water in oil... not fun). Picked up a used motor for $100. Dropped pan on 'used' motor and found most of #3 piston in bottom of pan (too far of a drive to take it back). Tore down entire motor. Machined head/block and honed cylinders. Polished crack. Engine rebuild kit... $600 later, I had rebuilt motor. My first. It's still running.

Could have saved some money on a good used motor, but I enjoyed putting the new 'used' one back together and I have a better feel on how everything works.

Get a GOOD factory service manual for the JEEP. It will cover entire engine rebuild and other things. Well worth the money!...

Good luck.

Plus now if something goes wrong you know exactly which part it could be, although its a little wierd thinking that the engine will last, hopefully, another 100-150k

CherokeeHelpMe · 01-25-2008, 08:26 PM

in response to crazydrivinjoe, im in fairhaven mass so you aren't that far away, and thank you very much for the offer of the old block. and in response to the sludge question, yeah, basically neglect, i wasn't driving it so i wasn't up on the maintenance and i really ended up screwing myself. but to look on the brighter side, now i have my project jeep.
and to add insult to injury, on my 98 grand, the alternator died and left me stranded on the highway for almost 2 hours in below freezing temps, but i at least can use the one from my 95, so no money out of pocket.
the whole idea of a stroker is pretty tempting, i just need to find someone local that can do the machine work for cheap.
thanks for the ideas and comments, keep 'em coming, i can use them.

CherokeeHelpMe · 01-25-2008, 08:28 PM

oh yeah, it has about 185k miles on the engine.

aaron7 · 01-26-2008, 07:10 AM

What year? New 4.0 shortblocks on ebay go for about $600.

indept · 01-26-2008, 11:21 AM

If it was bad enough to do that, you probably need all new pistons, new cam & bearings, new crank bearings, new oil pump complete valve job and total machine job on the block to be sure, Go for a new / used engine, you'll save money & time, unless you need something to do for a few weekends.

GoldenOne · 01-26-2008, 02:12 PM

Quote:

Originally Posted by driabyor

sludge = pennzoil
poor maintenance
.

No, that much sludge is not a result of just the brand of oil, its from ZERO maintence/thousands of miles w/o an oil change. Plus once the filter gets clogged up it stops filtering and the oil bypasses it completely. I'll bet it was more the use of a fram filter than the brand of oil.

throwing rods/sludge=fram filters with more than 8k miles on em.

**Trouble Maker** · 01-26-2008, 04:55 PM

Quote:

Originally Posted by GoldenOne

No, that much sludge is not a result of just the brand of oil, its from ZERO maintence/thousands of miles w/o an oil change. Plus once the filter gets clogged up it stops filtering and the oil bypasses it completely. I'll bet it was more the use of a fram filter than the brand of oil.
throwing rods/sludge=fram filters with more than 8k miles on em.

Is this from actual experience or from heresay that you read somewhere and are perpetuating the myth? Trying to turn this into another bash on Fram thread?

95% or more of the air, fuel and oil filters I and my immediate family have used have been Fram with ZERO failures due to a filter.

indept · 01-26-2008, 06:08 PM

Do a google search, Frams are cheaply made filters, they work but don't run them for more than 3000 miles. I found an article where a guy did an unscientific but good writeup on filters. he bought different kinds & cut them open to see how they're built. The cheapy Frams had a cardboard bypass valve, just a flap where the better filters including the higher grade frams had a metal bypass. seems to me a cardboard one probably has leakby letting dirty oil bypass it.