1986 Jeep Comanche 4x4 FIRST Project

[DesertComanche86]

Hello everyone,

 

Just purchase a 1986 Jeep Comanche 4x4 2.5L 4 Speed Manuel (the truck I have is #44,524 out of 45,219). My goal is to get it running again but I don't know if I want to keep it in its stock configuration or swap a 4.0 6 cylinder. I was just informed that there is leakage of water between the head and block. I know I will have to replace belts, hoses, vacuum lines, etc. It was sitting for about 3 years with the last owner. Don't know much more about it other than it was last registered in 2015. I have limited funds (about $6,000) and it needs a lot of work. I will probably have to tackle it little at a time (1. Engine bay, 2. Axles/transfer case?, 3. Suspension, etc.).

 

My question to anyone who has knowledge working on a 1986 Jeep Comanche, what can you tell me in terms of the best way to tackle this project? Should I keep it in stock configuration or swap for a larger engine? If I do swap, what's the best yet easiest swap (I'm not a mechanic so the difficult work will be done by a mechanic)? Anyways, just new to the forum and trying to brainstorm with the community.

[89 MJ]

As a 4.0 owner, I don't see any point of swapping to a 4.0. It would be a lot of work for mediocre gains. @eaglescout526 knows a lot about these 2.5s as well.

[eaglescout526]

Keep it stock for now and get the engine running reliably. The 2.5Ls are just as stout as it’s inline 6 siblings. Head gasket failure is common on these engines after they have sat for so long without having the water cycled through every once in a while. 

[NHMJXJ]

Looks like a good foundation.  You can do a lot with $6K too.  Take your time, start with the engine bay as you stated and keep her forever.  

[DesertComanche86]

Thanks for the recommendations. I think I'm keeping it stock. I just found a place about an hour away who can do the work it needs to get the engine and engine bay where I want it. 

[Pete M]

#44,524?

 

welcome to the addiction!   

 

 

[Classy Comanche]

Yeah I personally wouldn't swap the 4.0. Very good engines. Me personally I would look into your cooling component. Radiator, hoses, pump and coolant reservoir. If the truck sat for so long the Radiator may have issues or could cycle cruddy old coolant through the engine. I know with mine the first thing to go was my plastic coolant reservoir, then my hoses blew and then my Radiator went. Very solid and fun trucks to own. Just need maintenance badly seeing how old they are mine sat for about 2 years and wasn't ran maybe once a month. Any and everything you need should be on Rockauto.com or summit racing. I also highly advise staying away from plastic parts if possible, especially plastic coolant reservoirs. I converted over to a metal Mac tank from macs radiator shop and it's one of the best parts I've bought. Either way you got a good find, good luck!

 

Update: I just saw the pictures. You have a 2.5L and I own a 4.0. I unfortunately have no knowledge on those, the inline 6 engines are a bit longer and the radiator on them aren't sticking out like yours is. But nonetheless I'd still look into the cooling components first. 2.5's and 4.0's are very good engines. I still stick to keeping it stock

[luckycamper]

Hey man welcome to the club. I’m a little over a year into owning my own ‘86 w/ the 2.5 so I’ll drop my 2¢.

 

I’ve owned a few 4.0 xjs in the past so naturally I planned on doing that swap but after extensive research I scratched that idea immediately. It is not just a simple swap. A couple main reasons being 1)86 is the odd year so one effect of that is smaller engine bay—you’d have to beat the firewall in to accommodate the larger block, 2) the stock trans won’t hold up so you’d effectively have to replace the whole driveline, 3) new radiator mounts have to be fabricated to accommodate the 4.0 radiator. I could go on and on but unless you personally have the space, time, desire, and capacity to do it yourself, it’ll be costly. If you do the research and are still interested I’d say the way to go about it is to score a donor xj w the drivetrain you want. Personally if I really wanted an mj w the 4.0 Id just save up and get one. 
 

I chose to stay w the 2.5, at least for now. It’s not a race truck by any means but riding around town and in the mountains it’s fine. Keep in mind if you lift it and throw big tires on it, you’re going to lose a little speed and power.

 

Check out the other 2.5 builds on the site and see what they’ve done. 

[DesertComanche86]

Thanks for the advise. I've decided to keep it a 2.5L. Now my issue is finding a good interior for it. lol