IMPORTANT UPDATE!! Help Me Out!
 

I finally can get started on my XJ once again for sure.
This time am not stoppin till i get it running, Now since i have a job its kinda easier to get around things. Any wayss the engine i have right now in my xj is some ****, it had blown 2 rods and i woulda never found out if i never took the iol pan off, or the bigg knock it did when tried to start up. Soo i have to overHual that engine and get my self another working engine from My local Yunk yard, I might even buy another cherokee from a guy here on cherokeeforum and take that engine out of and just use the jeep for parts for mine. This is my first time overhualin an inline 6 from a cherokee so am kinda lost on the steps, I want to know if any body here has overhualed there engine, and put in a new or used one that started right up once installed. am going to be needing lots of help, Tips, Advice, Do's and Dont's. so please any thing you have about overhualing an engine from a cherokee and putting another one in, Let me know. Ill take PM's or on here it doesnt matter. i do have the Hanes repair manuel, but i want to hear it from some one that has done it in person them selfs. I have a 1988 Jeep Cherokee Laredo, 4.0 inline 6. So Please Help Me out Here with anything you have or know. Thanks

I rebuilt mine myself with the right tools and cash its not very difficult, I did not have to take the hood off to pull the engine out but it takes 2 or 3 people to do, and the easiest way to lift it out was to rotate the rear of the engine to the right of the vehicle and tilt the front up a little. and be sure to change out the oil filter adapter gasket while it is out or you will be pissed at how hard it is to replace with the engine in...
The camshaft i used was a COMP Cams Part: 68-201-4
High Energy™, 260H
Great for Towing, 4WD & Off-Road, Smooth Idle
Now if i was to just put a junked engine out of a yard :
I would inspect the oil on the dipstick,
pull the oil pan off and the main bearing caps to inspect the main bearings then go buy a head gasket and pull the head to look for cracks and wear, check play in the timing chain, ect...
you kind of have to weigh your options and cash because you might be buying another engine that needs rebuilt.
edit: also put a wrench on the front of the crank and make sure it rotates without too much effort and listen for any noises it makes
edit: also check the flywheel for ANY cracks.
im sure there is some more details someone will chime in ...

In my long experience with junkyard motors, don't buy it unless you hear it run! Often times you are buying someone else's POS motor and unless it's a rollover or total wreck, why is it in the yard? My advice to you is rebuild what you have. With a little care and lots of patience, you'll know what you have with no quesses.

I've had over 50 years of working on cars, many in the high performance field. I've drag raced, road raced, rallyed and offroaded. There is a lot of satisfaction in building it yourself, putting your own blood, sweat and tears into something you can be proud of. IMO there are too many off-the-shelf parts and custom engine builders out there and they are destroying the sport. Today, you don't even have to buy a car! You can build one from store bought parts!

I've ranted enough. My point is DIY, you'll appreciate it more.

Another point. The 4.0 is the most long-lived engine in jeeps. If you're going to rebuild it yourself, pay attention to details, do it right, and it'll last longer than you'll want it!

most important step to installing a used motor make sure it runs b4 you but it make the seller start it and let it run for at least a half hour to check for any un seen problems