Engine swap or Engine rebuild?

[brewer]

I have a 91 YJ 2.5 4 cyl. Currently 220K on the odo. Since the day I bought it, I have had a noise under the hood that makes it sound like a diesel engine. I drive into a gas station - the attendents try to get me to move toward the diesel pumps.

Over the last few months, the noise has started getting louder. I can now hear the knocking from about 50 feet away. This is fine with me since I just turn up the tunes and drive, BUT... it is causing me a little grief from the knowledge that one day this noise will no longer be there, and the vehicle which is my every day driver will be done.

So I'm left with a question - do I rebuild it? or do I swap it with something else?

Some factors to help the decision:

gas prices = stupid prices
Mechanical know how - I have some, but nothing of this magnitude
Location = I live in Vancouver and know next to zero mechanics, thus no idea who is trust worthy and who is a scammer.
Value = the jeep's in decent shape, but not emaculate - but I've always loved jeeps - so to me, I want to fix it, but the value screams don't do it.

If it's a swap - I want to be in there helping, cause I would find it very informative, not to mention it would help if something broke I knew what was original and what was modified.

I guess my question ultimately brings me to ask you guys - if you were in my shoes - what options would you take? I thought about just changing the lifters and cam because I understand this is where the noise is coming from - but some mechanics tell me it's pointless because if I fixed the upper half, the odds are the lower would then need fixing too - kinda like pouring wasted money into it.

What would be the ideal engine to find? as in cheapest, most abundant for parts, and simplest to install - also baring in mind I would then need to buy all the add ons like carb / injection, transmission, etc etc.

Please help me figure this out.

thank you

[yj40swapped]

without the proper no how your better off finding a junkyard motor.. rebuilding a engine isnt hard.. however... for the average joe... one simple mistake can mean the ends of a rebuilt engine. when I swapped my 4.2 to 4.0 I paid $900 for everything... engine, computer, map sensor.. motor had like 44k on it... been 20k miles and still running strong. If you dont know what your doing.. dont attempt an engine rebuild.. it will come back to haunt you.

[ovrlnd]

personally I would swap. you can buy a brand new 2.5l from jcwhitney if you like and just put it in. there are plenty of easier swaps. 4.0, 4.3, 350, 500 cadillac (only kidding)
anyhoo I would go with something that had a little more gusto.

[goatboy]

In your situation, I'd go find a mechanic who could source and install a Jasper engine...In MY case, I'd take the original engine and rebuild it my own self, and have the machine work done by my local and reliable machine work...At the end of the day, I'd know EXACTLY what I had, what was done, no questions, and everything would be top of the line...but that's me, and I'm not you...but I don't think, based on your description of your abilities, that you want to try this... If cost is an object to you, then you need to sit down with your legal pad and pencil, and figure out what you have into your vehicle NOW, what you would have in it after the work, and what you figure you could get out of it...If, on the other hand, you are in love with your vehicle no matter what, then just do it... Ultimately, this is something that nobody can really advise you on... It's a seat of the pants decision...in my case, I will probably have more into my YJ that what I can get out of it, and in the best case scenario, it will come out just about even...after repairing the engine to get it running, installation of Mopar fuel injection, installing a 2.5" RE lift with MORE shackles, having the transmission rebuilt and the TC resealed...and a myriad of other little thangs... But, hey, I like the vehicle... and at the end of the day, I've got a very dependable platform...and for a lot less than I could spend for a new Jeep...

[brewer]

Thanks for your help guys. I'm of the mindset where I'm thinking the likely route is to fix it - at whatever the cost. Fixing it in my book is putting in bigger and better though. I figure fuel economy right now already blows, so adding a bigger engine can't be all that much worse. I'm getting about 300 kms to the tank right now so for a 4 cyl, I have terrible fuel milage and nothing in the way of power. I've got a couple people that might be able to help locally find me the right fit - but if anyone out there is from Vancouver - or has some advice where to look - I'm all ears.

cheers

[bwiencek]

I wouldn't do anything until I had a trusted / referred mechanic take a good look at the engine - it could be something as simple as a broken valvespring, loose rocker arm, etc. These fixes are relatively cheap and I would assume that since it's been running this long while making the noise it's not in the lower end bearings (which should have failed by now!)

That said fixing the simpler problem will result in better economy when all the components are working well.


If they do find out it's something in the lower end (bearings) then you've got to make the decision on what to do. In this case I would suggest findind a 4.0L equipped wrangler YJ for an engine swap - they get as good if not better mileage than the 2.5L, have a lot more power, and are definately high on the reliability scale if maintained. You can use a cherokee, but finding a wrangler will make the wiring a direct plug-and-play operation. The cherokee is an easy swap, but the wiring changes can intimidate some folks (they're well documented and easy as long as you take your time and be sure to check twice and cut once!). Really the only hard part about the swap is relocation of the motor mounts to fit the 4.0L's location - and that will require welding. The up-side is any jeep dealership will be able to service the engine, you won't get funny looks if you have an inspection program in the area, and the resale goes up with the EFI 4.0 in it vs the 4-cyl (at least around here it does). I picked up my complete cherokee donor that was wrecked in the rear for $250 and after using the parts I need and parting out the rest dirt cheap to get it gone I stand to MAKE $200-300 on the deal... how's that for frugal You might be able to trade some of the extra cash / parts for labor to weld up the mounts for your swap.

[brewer]

bwiencek - thanks for that. I'll be taking it in to some form of mechanic before I proceed with something as extreme as an engine swap. I do know the engine has added 50K onto the motor since i got it, and all the while making this noise. I would also be shocked if it was something major. Heck, I wouldn't be shocked if I could gete another 40K on it the way it is right now - so I'm not in a panic - just getting a small amount of concern built up before I go bananas. Not to mention getting some homework done before I have to - in case I'm wrong.

now to find that ellusive trusted mechanic....

[84 400]

lacking know how the cheapest easyest route is to swap in the exact same thing that came out aka a 2.5L from a same year junk yard jeep. That would be the cheapest and quickest. However it seems like you want to upgrade. As mentioned above you need to find some one you can trust and hopefully that person also happens to be a jeep nut.