The engine i want to put in is a 4.2 in line six from a 1988 Jeep Wrangler, i am needing to replace a 2.5 four cylinder for a 1995 Jeep Wrangler, what complications could i come upon with switching these engines out?
Nothing but Jeeps
The engine i want to put in is a 4.2 in line six from a 1988 Jeep Wrangler, i am needing to replace a 2.5 four cylinder for a 1995 Jeep Wrangler, what complications could i come upon with switching these engines out?
{ 3 comments… read them below or add one }
This isn’t a very common swap, going to a 4.0L is better. However if you already have the 4.2L you’ll need the tranny, wiring harness, computer, sending unit, exhaust head pipe, motor mounts and possibly gears for your axles depending on what you are doing with the jeep. The 2.5L ran 4.11 gears and the two straight sixes ran somewhere in the 3s. The carbureted motor doesn’t get great gas mileage. You don’t want the Puegot BA10 that tranny that came in the ’88. The Aisin AX-15 is much better however in ’92 or ’93 the pilot diameter size changed and the reverse gear was beefed up but you’ll need a new pilot bearing to run the newer tranny as well as an external slave cylinder. Check out a few jeep forums, some guys do this swap and I’ve seen a few write-ups about it.
My neighbor wants to do this to his YJ as well. The closest I cam find for this swap is going to a 4.0L. The link I provided below shows the motor mounts, transmission, most of the O2 sensors etc. I read a bunch of threads that say it is cheaper and easier to sell the 2.5 Jeep and buy one with a 4.0 but that is not always possible. Also check out the jeep forums I am sure someone has already done it and there is a write up there, i just couldn’t find it.
Also since it looks like your putting an older motor in, I am sure your going to rebuild it. You may want to see if you can find a newer 4.0 motor and build a stroker. I found my donor 4.0 on craigslist for 150.
http://www.jeepstrokers.com/forum/
http://www.angelfire.com/my/fan/stroker.html
http://www.jeepsunlimited.com/forums/index.php
http://www.jeepaholics.com/tech/25to40/25to40.htm
the 4.2 will fit pretty much straight in. you will need new motor mounts. the tranny will not bolt up. the 88 wrangler had the piece of crap peugot tranny, the 2.5 95 wrangler had the ax-5 tranny, (those are the manual transmissions) You will need to get the ax-15, which Im sure is a straight bolt up to the 4.2. on top of that be sure to grab the ecm, all the wiring, your pretty much changing everything under the hood and alittle farther back. but to answer your question on if it will fit? Yes it will. very easily in fact.