My fiancee has an 08 JK Rubicon 2door, and she loves it except for the gas motor. Bein that we're all farmers, me, her little brother and most of our friends all got diesels, and she wants one, too. I know she could sell it and get something we a diesel, but this jeep kicks ass. I contacted AEV, the company that makes the Jeep TJ Brute kit, because they do some amazing engine swaps, but they said right now it isnt cost effective to do a diesel swap in a JK, or something to that effect. Basically, its too damn expensive, which is ok cause i knew they would be. Anyway, we were looking into the 2.8L from the Jeep liberty, but how hard of a swap is this? Does anyone have any info on a swap like this? How hard would it be to put an older diesel, like an older nissan diesel, or a 4BT cummins? Or maybe an old tractor motor like a 4 banger Perkins, cause theres a guy here in GA that puts old tractor motors in trucks that get 50MPG. Putting the motor in the jeep i imagine would be the easy part, what about all the electronic crap on the Jeep? We would love to get a deiesel in this thing, especially since we're looking at makin bio-diesel. We might not have an unlimited budget like some folks do, but we got a little enginuity, so it might happen. Any help would be good. Oh yeah, this thing is a daily driver, so an engine thats not too loud would be good. We are big time cummins folks but that probably rules out the 4BT, Jeeps arent known for being quiet, and a loud motor would make it even louder  

I remember reading a story a while back that Mopar was offering a diesel swap kit for the 2.8L out of the Liberty. Supposedly it'll fit into almost any Jeep from the mid-'90s to today.  

Ill have to look into that, thanks esanchez!