Engine swap questions 5.2 and 5.9.

[Andrew XJ]

some of you may know but most of you do not my 4.0 is in the process of dying I severely overheated it for about a half hour so here's the story, I went to a mud bog and got mud stuck in my radiator fins so it was not cooling I forgot to spray the radiator off before I drove home. My check gauges light flashed and I heard an audible BEEP to let me know that I was overheating I looked at the gauge and it said 210 which is normal for me when it's hot outside so I thought nothing of it, like an idiot I might add, so I kept driving for about 30 minutes until it BEEPS again and I looked down and it was pegged out at 260°+ so I immediately pulled over and waited about 2 hours to let my engine cool down once it cooled back down it started right back up with no problem but I only had about 5 psi of oil pressure but I had to drive home I have no other option I'd spent all my money to go to the mud bogg and did not have enough to pay a tow truck to haul my Jeep 50 some odd miles back home. so I had to drive her home, well by the time I got home the valves are rattling and knocking there's no oil pressure no oil to the topend I let it cool back down put Rotella 15-40 in it and a new filter started up still no oil pressure valves make terrible noises and I have definitely lost some power, so far I have isolated all the noise and rattling to the topend, unfortunately I can't afford to buy a new top end and my local junk yard is fresh out of 4.0s but they have plenty of 5.2 Magnum v8 and 5.9 v8.


Nnow to get down to the point of this post which was, will either a 5.2 or a 5.9 bolt up to my stock a w-4, it's brand new just been rebuilt and I really don't want to replace it, now I know what you're thinking just rebuild the 4.0 well believe it or not it's cheaper to go to my junk yard and get a v8 and harness then it is to rebuild my engine what's even nicer is that they mark running and non running vehicles with the current odometer mileage written down as well.

I also need to know what all would be required to do the swap, I understand the engine harness the computer a different radiator for the bigger engine and dule electric fans more than likely due to lack of space.

on a side note I was thinking about doing a 4.3 swap there's a lot of them as well but for some reason nobody sells an adapter for the automatic transmission.

[4.3LXJ]

Andrew, the V8 swap is cool, but not for the faint of heart. As far as the 5.2 swap goes, you can do it, but you will have to move your tranny forward and there is no way that XJ radiator will work. It will take some expensive custom radiator or redo the cross member and use a ZJ radiator and ZJ cross member. Now as far as that goes, there is a problem with the dash stuff working etc. The best thing I can suggest is follow my thread on Project TJ Resurrection. I am currently installing a 99 4.7 from a WJ into a 98 TJ. In order to make your electronics work, it is far better to keep to the same year or nearly so. Also plan on getting some factory service manuals, mine are on CD. There is some wiring to do and if you do it using these you can keep it real clean. But still you will have to fabricate motor mounts etc.