Engine Swap or Rebuild?

[Jax MJ Luvr]

OK, so I'm not very grease monkey inclined. So I'm the dork that'll probably end up having to pay someone else to do it, but my 92 MJ either needs to be rebuilt or swapped out. I'm fishing for advice as to my best route and/or bang for the buck.

 

I live in Jacksonville, FL, my Jeep is still in Colorado Springs, I moved out here last year, but had to leave my Jeep with the parents. I plan on flying back to either tow or if there's enough life in the engine, drive it back... it has just over 220000 miles in the old gal. She flutters and conks out after the 1st start, but runs like a champ on the 2nd start.

 

I finance "credit challenged" people for cars for a living, so I have a bunch of dealership hook ups that can get me a good mechanic, but heck, if someone is nearby me, I'm willing to put in my own labor and learn how to do it with guidance of course.

 

Any and all help/advice is appreciated.

[JeepcoMJ]

what are you basing your info on? that is to say, how do you know the engine is junk rather than in need of some minor parts replacement? 220,000 miles is no excuse...the engines last a long time, unless thoroughly abused.

[Wildman]

I don't know if this is really a pole?

 

As Jeepco wrote, have a Good trustworthy mechanic check it out first. It could be a bad fuel pump, bad coil, bad sensor?

 

I guest the real question is, Is the whole truck worth it?? Body good, drive train good, some real sentimenttal value?

 

A ball park price to swap a good used engine in, paying some one with additional parts needed would run around $900 - 1200.

 

300-450 for used engine, 350 plus for labor, and other needed parts, plus you want to change all of the gaskets and seals while the engine is out and you might need additional parts, water pump, radiator and all new hoses, new wires, plugs, and room for other new parts..

 

I don't know the price on a re-build motor, others should know.

 

Do you have connections in Florida or Colorado? Towing it what 1600 miles would not be a choice, I don't think I would trust it on the drive, road side brake downs get very expensive (I know :roll: )

 

If you can get the engine swap where the truck is, then drive it to Florida, that would be the best choice IMO

 

Some one on a local board did their own engine swap, with some "help" and it's been 2 months and still not done. A shop should take 2 days max to swap an engine.

 

What you need to look at is the truck worth it? The value of the truck as it sits now, and what the value would be with a "newer" engine in it, yea a running truck is worth alot more that a parts truck. A parts truck is worth $200 around here, and in good shape, good running $2,300 with NO rust, and road ready.

 

Stick with the 4.0, more of a direct replacement, plus a great engine. ;)

[87manche]

last time I looked at 4.0 remans the going rate seems about 800-1K bucks for a longblock.

This of course included no oil pan/valve cover or accesories.

 

I second the "are you sure it's the motor" question.

Mines got 260, starts up everytime and makes good oil pressure.

[mudrunt]

My brothers xj had 280000 on it before it gave up. Still ran good just lost power one day. Pulled the head off and found #3 piston had a hole in it. Priced long block around here and they ran about 1500 bucks. Found a block from a 96 with really low miles from a wreck, honed and re ringed it and runs like a champ now. took about 2 months to pull rebuild and put back in.

[Pete M]

Give us some more details about the problem! :thumbsup:

[fiscus]

I've replaced a couple 4.0L motors in a weekend, they're pretty simple to pull & replace yourself in a garage. Hopefully someone local to you (or the truck) will come forward to do the swap. You can usually get a wrecked XJ with a good 4.0L for cheap.

[Jax MJ Luvr]

well I bought it for a whopping $996 , it's the 4.0 HO, it has the metric ton package, so a nice D44 in the rear, it's been my project truck for about a year... I've been driving my reliable Scion for the time being, but now that the wedding is coming up soon and we're looking to start the family, we're trying to cut out whatever long term expenses... so I'm selling off the car and just fixing up the MJ once and for all and make that my new reliable vehicle ;) There's no rust on the frame, the bed is banged up, but fixable, the interior has been redone, so far just did the basic full fluid changes when I bought it over a year ago, but no major tune up yet... leak oil like crazy, idles rough, the engine fan will come on and never goes off, but never overheats either... the last bit of advice I got was to have the "bottom end" rebuilt if I planned to lift it, otherwise I risk blowing out the motor... I suppose I can just have a real mechanic go over it with a fine tooth comb and find my real problem spots, but with so many miles I'm hesitant to lift and do what I really want with it in fear of blowing out the motor with so many miles on it... I'm not sure what it can really handle safely... so for me... an ounce of prevention... so to speak... I suppose I ought to call my dad and get a reliable, honest mechanic to give it a good once over maybe...

[Pete M]

Before you pay someone to work on it, try some of the easy stuff, like cleaning the throttle body, giving it a basic tuneup, etc. Stumbling is not generally a problem with the engine block, but rather a fuel or spark delivery issue. If you don't fix the problem now, you will still have it after swapping in the new block and will have wasted a ton of money in the process. The 4.0L is a very tough engine and has proven time and time again that it can go way beyond 200k. And lifting the truck will not kill your engine. Ever.

[87manche]

I completely agree with Pete.

Your stumbling just may be spark plugs gapped wrong.

 

and it's not lifting the truck that kills the motor, it's what happens after you lift it, like running it on it's side, or upside down, or under water ;)

[feerocknok]

Bigger tires without regearing puts more stress on the motor as well. Also, wider tires create more drag.

 

Yeah, go over the basics. If you still have issues, bring it to a mechanic. If the motor is indeed going out, try to find a Cherokee for the cheap that has been wrecked and grab the motor from it.

 

For what it's worth, my I-4 long block was $1200 with a 3 year/36000 mile warranty.

[Jax MJ Luvr]

cool, I appreciate all the advice. I do recall when I had it in for the smog check, they said that the fuel mixture was running a bit rich. Not sure if that would cause other issues related to what's already being experienced. I still am concerned about the fan not ever turning off though... once the engine warms up, it'll click on, but never turn off... ever... until I shut off the motor... my previous 94 Cherokee never had that problem, so it makes me wonder if maybe the temp gage is functioning at all or if it's just a simple electrical issue... hmmm... anyways, it's out in Colorado, so any work on it and diagnostics may end up having to be by a mechanic out there, since all I can really do is just ask my dad to take it into his trusted mechanic for a check up and diagnosis.

 

here's a pick of my baby after I replaced the rusted doors :)

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and the nice oil leak puddle below :P

[Pete M]

I wired my fan to a switch (through a relay) and I leave it on all the time. It won't hurt the fan, but you should probably still find out why it's doing that. Ya never know when it might decide to stop coming on. (that's what prompted me to wire in the switch) :D

[DirtyComanche]

The factory AUX fans are basically posessed. They do what they want.

 

 

In my XJ it would come on when it was -30~ (or colder, I hadn't checked until recently) out as soon as I started it.

 

 

 

 

And it just sounds like you need a tune up. Clean the injectors, clean/gap/replace plugs, check the dist, clean the TB and IAC, clean/replace the air filter, check all the vacuum hoses for breakage/blockage. Basically do everything I never bother with.