replacement engines - what to look for

Bill F

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I bought a low mile 02 KJ last year with a seized 3.7 (blew a head gasket and they kept driving it). From my readings, the head gaskets on these were a weak point. As I go to various wrecking years or check with used engine suppliers, what should I look for (if there is such a thing) that will tell me or show me if the engine I'm looking at has a similar pending HC failure?

thanks
Bill
 

LibertyTC

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Always best to find another 2002, for matching sensors/electrical. Problem is they are all high mileage.
In my honest opinion for longevity and a warranty, I'd consider Jasper engines, with shops across the USA.
Many members have gone this route with great long term success, and then have a headache free eninge for many years ahead.
 

WyldWolf777

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I bought a low mile 02 KJ last year with a seized 3.7 (blew a head gasket and they kept driving it). From my readings, the head gaskets on these were a weak point. As I go to various wrecking years or check with used engine suppliers, what should I look for (if there is such a thing) that will tell me or show me if the engine I'm looking at has a similar pending HC failure?

thanks
Bill
I would try to find one with low mileage under 150,000 to start
 

Bill F

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thanks but the one I bought only had 131k. The thoughts I'd had so far were to pull plugs and look for one(s) that were really clean. Or the obvious chocolate milk or chunky oil. Just looking for other tells. Also, my understanding is 2002-early 2004 were swaps (but primarily 02 and 03). Sometime after Christmas I read where they changed the stator and the VC pickups

thanks
Bill
 

WyldWolf777

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thanks but the one I bought only had 131k. The thoughts I'd had so far were to pull plugs and look for one(s) that were really clean. Or the obvious chocolate milk or chunky oil. Just looking for other tells. Also, my understanding is 2002-early 2004 were swaps (but primarily 02 and 03). Sometime after Christmas I read where they changed the stator and the VC pickups

thanks
Bill
I recently bought one from a junk yard with 124K and they did a thorough check before selling it of compression, leaks, unusual noises. Everything checked out great and it runs like a top
 

Robochop

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If you have the equipment or access to it, I have found it's better to pull the engine and rebuild it. I have done it myself on several occasions. My local machine shop can take care of the heads, block and crank. They will even rebuild it for you to put back in. I think it's better than spending a thousand or more for a junkyard motor. With regular maintenance and upkeep, it will last you 300K miles and you don't have to be an expert mechanic to do it!
 

Bill F

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Robochop - I did consider that - even went as far as to pick up a rotating core to build (since I knew mine was seized). BUT... I do timing chains on Jag engines quite often. BUT that mess scares me! I've watched several videos on the 3.7 chain installations, and holy **** thats a ******* up nightmare
 

Robochop

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LOL, I understand! Once you start doing it, it goes pretty easy. I have resurrected plenty of Liberty's and have purchased several of the tools required, especially the camshaft holding tool. The other ones they recommend are not needed. There are many aftermarket engine rebuild kits for $300-500. The machine shops costs are usually under $500, which translates to a complete rebuild for less than $1000.
If there is not that many miles on it and the cylinders look good, you can get away with only doing the heads and timing chains. The only thing I hate is that you can't see the oil pick up tube screen. They tend to get gunked up if oil is not changed regularly. I am in the middle of a rebuild for a 2005 Limited that I picked up on craigslist for $1000. it's got beautiful paint and interior, new tires, chrome wheels, new A/C and ****** was rebuilt by the dealer!
Feel free to msg me on any questions!
 
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Just purchased a 2002 Liberty with 259,000 miles on it. Transmission was rebuilt 2000 miles ago, new starter, alternator, A/C, and a bunch of other new stuff. Previous owner took good care of it but motor just broke a piston and needs replacement engine. I saw this thread and wonder what the original poster found for replacement engines?
 

lfhoward

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Back in 2014 mine had a failure that necessitated a new engine. I had the mechanic install a Jasper remanufactured engine. My overall impression is it is quieter and more powerful than the original! Also they come with a 100K/3yr warranty on parts AND labor. It is more expensive than a junkyard motor but you’re not rolling the dice. I have 105K on the new motor since then, and it has been awesome.

If your 02 has a clean rust free body and a nice interior, and you want to drive it for a while, consider a Jasper.
 

Bill F

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Just purchased a 2002 Liberty with 259,000 miles on it. Transmission was rebuilt 2000 miles ago, new starter, alternator, A/C, and a bunch of other new stuff. Previous owner took good care of it but motor just broke a piston and needs replacement engine. I saw this thread and wonder what the original poster found for replacement engines?
Bahama - I haven't decided yet. I am working on the core I picked up (as far as stripping it down) just to learn these. If my confidence level goes up a tick or two I may just have a go at it. Problem here local is two of the best machine shops have shut down or are not taking any new work getting ready to shut down (retire). So that may in of itself change my direction. I'm set up to do valves/guides/seats (I have an old Sioux machine) but I'm not set up to plane if they need it. If I buy a replacement, it will be a Jasper. They are about $800-$1000 more than others on the web, but none can match they're warranty. I have a Jasper transmission in my truck right now (same warranty - 3 yr 100k mile) so I an a returning customer. My only drawback was with the low miles on this unit I was planning on flipping it. If I drop in a Jasper, I'd be right at the top of my break-even on it. So I may have to drive out some of the goody to get a bit of return as I don't really know what, if any, extra return would be on the extended warranty on the open market.
 
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After a partial teardown of my engine, it will need a new cylinder head and block at a minimum. the #4 piston completely disintegrated, and the connecting rod and pin banged a hole through the cylinder into the water jacket. Never seen one fail like this. The valves for that cylinder all appear intact and not bent from forced contact with the piston, but the flying shrapnel from the piston just pounded the head, so it's not worth repairing. I found a broken crank to balance shaft chain tensioner, and the chain was pretty floppy, but did not appear to have skipped a tooth. Both bank 1 and 2 chains and tensioners were intact, and it did not appear that a valve timing issue initiated the engine failure. I'm very comfortable rebuilding engines, and rebuild parts are cheap for the 3.7L, but this engine is just too destroyed; I'm not even sure it would credit as a core.

I'm in the same boat as you, Bill F, in that I would like to flip this car with a new engine, but I'd lose money on it with a $4,200 Jasper Engine. I bought the Jeep for $500, thinking I would use it's rebuilt 45RFE transmission in my 2005 Liberty, but that car uses the 42RLE transmission, and swapping it would require all kinds of electronics and wiring changes, so in that case I just rebuilt the original 42RLE, and now I have to decide what to do with the 2002. The rest of this car is in great shape (new tires, great interior and exterior, 4 wheel drive; everything works, plus it has new starter, alternator, AC system, etc.), but it's a high mile, 20-year-old car, so there's a limit to what anyone will pay. I think with a new motor and transmission, this car would only bring $4,500 at most, so you're limited on what can be spent on it. The only thing that could change that is continued COVID craziness keeping new and used car prices grossly overvalued. In that scenario, who knows what someone might pay, but stuff is going to break on a 20-year-old car, and people know that. New motor and trans just means you won't have a big $ repair, but U joints, differentials, wheel bearings, transfer cases, etc. could all go at any time, so I don't think this car could ever bring $6,500, which would be my minimum to cover parts and labor for a Jasper engine.
 

Bill F

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Must be a shipping difference - I got quoted $3,600. I'm in the 02 Lib for $500 (it was on its way to a wrecking yard when the driver stopped at at my Son-in-Law's (one of his buddies) just to chat. Son-in-Law called me, I told him if the miles were right and it was clean do it. So the driver dropped it right in my SiL's driveway. Engine plus purchase plus odds-n-ends gonna put me probably north of $4,500 which is really close to the top of the market locally (I think KBB was $4,680 if I remember). A 20 year old unit isn't gonna get financed so the size of the market gets cut down fast when the numbers are that high.
 
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Pretty much what I found also in the resale market. I guess the short answer is you can’t flip a car like this expecting to make money. You either want it to drive yourself or for parts. They’re dang good little go anywhere cars, though. I’m now leaning towards a local junk yard motor for $400-$500 and just drop a rebuild kit in that. I think these motors are tough enough that you could lightly hone the cylinders and put new piston rings, bearings, chains, tensioners, and oil pump in it, and the bottom end would be solid. My current motor with 259,000 on it still has nice cross hatch on the cylinders, so I expect a donor would be similar. I also think that if you don’t see any evidence of leaking head gaskets (like coolant in oil or white crusty stuff around the head to block, then machine shop work may not even be required. , but that’s a big if. Rebuilt cylinder heads seem to be common. The heads seem to be the weak link on these engines, but that’s probably because so many fail the water pump and overheat. I’d say you just have to assume any used engine has been overheated and go from there. As much as I would love to just drop a Jasper engine in mine, that blows the whole budget, and there will be lots of additional repairs needed. A nice motor does very little for you, if a differential or wheel bearing takes you out of commission down the road. Just my $.02
 
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I ended up buying a rebuilt longblock for $2k from a shop in Florida. Cost was around $2K and included all gaskets and seals plus a 1 year warranty. That’s probably not worth the paper it’s written on, but at least the motor looks to be built properly. Not Jasper quality, but cost is much more in line for a car this old, and it will certainly outlast the car. I’ve got to use the valve covers, oil pan, and timing chain cover from my old motor, so the lower cost comes with some extra cleanup
 

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