Saharacon

I havent had much time to post recently, but I want to keep things moving while they are fresh. I am attaching an overview of which connectors are new, and which ones need to be spliced or rewired. I will provide diagrams to match the wires soonish.

robertgreen79

My friend Mark met you the other day and was telling me about it. Its awesome to see its possible. Looks like a crazy amount of work though! I'd probably be going with an auto (currently have a manual) so it'd be even more difficult

Saharacon

This project was pretty involved. Out of the time spent on it, by far most of it was doing research before I started. Actual wrench turning time was split into 4 equal time categories: 1) Actual work, 2) removing parts without the correct tools cramped under the jeep, 3) working out the kinks, and 4) doing upgrades (which I havent talked about yet). The total project took me five weeks of working occasional nights and about 8-14 hours each weekend. Without categories 2-4 I would say the actual swap if I had to do it over again would take less than 40 hrs of labor.

As for swapping your pre 2012 manual for a post 2012 auto might be impractical. You may need to change out the old TIPM to a modern era TIPM for an automatic tranny that exactly matches the features you have in your wrangler right now (power windows, locks, cruise, whatever). If that were the case, the Dash wiring harness has significantly changed (for the climate control reasons), so that would have to be accounted for with the new TIPM. So you while I basically had to change the entire engine bay out (except power steering), you might have to change the dash out also if you switch to auto. When I get time to post the wiring here, I will look at the auto tranny logic to see how much the TIPM controls things vs the PCM. If its just a couple functions you may be able to improvise.

Also, I do have a pile of left over good parts for those who want to keep their 3.8L running, or want a running engine/tranny/NP241J for a core.

Almost There

"If I had 140 hours to do an engine swap,
I'd spend the first 100 hours doing research."

- Saharacon

Coxie1969

He said less than 40 hours not 140

Ajkaz

Are you up and running? I'm assuming the 3.8 and 3.6 use a different bell housing?

Saharacon

I am up and running. And yes, the actual swap only took about 40 hours, more time only when you consider research and other mods. I have about 1000 miles since the swap. I have been intending to post wiring diagrams for the bold of heart, but that involves more of my time. I will get more technical details up when I can.
The two most pain in the neck issues so far have been the need to add a fuel tank pressure sensor, and the need to add the vacuum booster to the brake booster. These two items annoy me because they are totally unnecessary to the function of the vehicle , but will need to be done to get some dash lights to turn off. After 1000 miles of all kinds of testing, neither has negatively impacted performance or emissions. I just finished installing the fuel pressure sensor, and the vacuum booster will be next.

fredrok

Wow, great read and kudos to you for doing "what can't be done". Also, thanks for a great contribution to the community by taking the time to document and share. Good job man!

Wait......a JK-Forum thread where no one is throwing insults!?

Coxie1969

So since you have 1000 miles can you say it was worth the effort?

Invest2m4

Id be curious what the total cost was. And I mean no BS, all in. My 3.6 with 5.38 gears and 4:1 transfer case, sucks ass offroad. Can't even spin the tires in 1st and lo. I'd rather have a 3.8 with a roots style S/C.