Time for a new engine

[canon07]

My 1989 YJ with the 4.2 i6 backfires and stalls and has zero compression in cylinder 4.

The engine was rebuilt 3 years and 10,000 miles ago and hasn't really run well since. I think it was just a poorly done job but I didn't own it when the work was done and there's no warranty of any sort left on the work.

I'm leaning towards just getting a remanufactured 4.2 - it's the cheapest option when you consider all the other parts any sort of swap would entail.

I have been using her as a daily driver with maybe a dozen or so wheeling trips thrown in every year. I live about 4 hours from Moab and Sand Hollow is in my back yard so we do a little crawling. I took her to Moab a little over a year ago when I first got her and she did great on the easier stuff with he 31" tires and stock axles. I would like to eventually upgrade to 33s or 35s and do the Ford 8.8 axle swap but that's on the back burner now that I'm replacing the engine.

So my first question is, has anybody bought a remanufactured engine from Powertrain Porducts and how was your experience? I'm looking at this engine, 7 years on the warranty is what really has me leaning towards them: https://www.powertrainproducts.net/product/1987-1990/#year_make_model_part_engine

My second question is, will I regret not swapping when I had the chance? I've gone down the rabbit hole researching a TDI swap, contemplated the LS swap, and looked at prices on a 4bt cummins and they all seem like they will run me at least triple the cost of replacing the 4.2. Are they that much better than the 4.2?

I figure the TDi swap all-in is the cheapest swap option but even if I got a junkyard TDI that looks nice and runs great, a 7 year warranty on the 4.2 sure would make me feel a whole lot better than taking my chances on cheap engine. And with all the additional parts I'd need, it'll still be at least a couple grand more than the 4.2... although 30 miles to the gallon sounds way better than what I get now. But that would be a whole lot of gas I'd have to buy to offset the upfront costs.

Any thoughts would be appreciated.

 

[dodgerammit]

I did a 4.8 LS swap on my Wagoneer almost 3 years ago. All in, I was at $5K. That was fuel tank, AN fuel lines compatible with ethanol blended fuels, fuel filler hose, driveshaft (rear) engine ($1800 verified runner), transmission adapter ($500 since I'm rocking the 727), coolant hoses, PCM flash, and all the other miscellaneous bits. I did all the wrenching. I do plenty of vacations and road trips in it, so cost wise, it is justified for me since I can get Gen 3 GM engine parts anywhere. Most of the time the parts stores have whatever on hand for immediate purchase. Kinda nice if say the alternator or water pump craps out, I don't have to wait 3 days for their warehouse to ship something so I can get back on the road. I've logged around 20K miles since the swap. Just get in, turn the key, and go.

In a YJ, I'd consider a 4.0 swap before a LS, but that's just me.

 

[Stoopid Jeep]

You should remove the cylinder head and take a peek inside. A head rebuild and/or a new cam would be cheaper than a whole motor.

**edit
Actually, I would probably start with a leak-down test

 

[DOWNS]

I'd certainly start with some trouble shooting before replcaement but it sounds like it's been a problem engine from day one.

I Just ordered a TITAN Engines 2.5L for my dad as an X-Mas gift for him. Still not here yet, probably won't be here till after the new year. After the core charge, we were in the 2500 range I think. Shipping was basically free because they were running a promotion that knocked 300 dollars off.

 

[canon07]

I did a 4.8 LS swap on my Wagoneer almost 3 years ago. All in, I was at $5K. That was fuel tank, AN fuel lines compatible with ethanol blended fuels, fuel filler hose, driveshaft (rear) engine ($1800 verified runner), transmission adapter ($500 since I'm rocking the 727), coolant hoses, PCM flash, and all the other miscellaneous bits. I did all the wrenching. I do plenty of vacations and road trips in it, so cost wise, it is justified for me since I can get Gen 3 GM engine parts anywhere. Most of the time the parts stores have whatever on hand for immediate purchase. Kinda nice if say the alternator or water pump craps out, I don't have to wait 3 days for their warehouse to ship something so I can get back on the road. I've logged around 20K miles since the swap. Just get in, turn the key, and go.

In a YJ, I'd consider a 4.0 swap before a LS, but that's just me.

When hunting for a 4.0, do you need to get the OBD1 engine? Or can you go all the way up to an '05 Wrangler to find a donor? Is the reprogramming that much of a pain on the OBDII?

 

[machoheadgames]

When hunting for a 4.0, do you need to get the OBD1 engine? Or can you go all the way up to an '05 Wrangler to find a donor? Is the reprogramming that much of a pain on the OBDII?

You can use up to a 1999 TJ engine or up to a 2001 XJ engine. The XJ was discontinued after 2001 and the TJ changed blocks for 2000.

Only problem with an OBDII motor (96+) is that the cylinder head is not drilled for the temp sending unit that runs the YJ gauge, so you'd either need to use a tee to install the sender up at the thermostat housing, or you'd drill and tap the head. Or just get an older motor.

For the record, I am saying all of this with the intention of you installing the YJ stuff on whatever engine you choose and running it OBDI. Between the different fueling different wiring harnesses, I would stick to OBDI and not try to do anything OBDII.

 

[dodgerammit]

For the record, I am saying all of this with the intention of you installing the YJ stuff on whatever engine you choose and running it OBDI. Between the different fueling different wiring harnesses, I would stick to OBDI and not try to do anything OBDII.

In your case, since you have the 258 and would be swapping to a different motor, I second what Macho stated here and use something up to 95.
This unfortunately limits availability, but there are donor vehicles out there.

If you do choose this route, you will need the engine harness and pcm from whatever you get it from.
It will be more involved for sure.

The only real question is what do you want out of the Jeep? Daily driver would be worth the time and expense, imo.
Fair weather cruiser? Then K.I.S.S. with a remanufactured unit.