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4.0 engine..Other applications

rattler43

NAXJA Forum User
Was curious as to whether or not the 4.0 engine was used in other vehicles other than the jeep. Such as Chrysler autos or other. The few xj's that I find in our local pick-a-parts look like a turkey the day after Thansgiving. Anyone out there know of any other sources? Thanks Don
 
I'm about 99.9% sure the 4.0 was only used in Jeeps,although I can't imagine why, it's a far superior engine to the 3.9 V-6 they used in the dodge trucks. As far as I know the only place you'll find them is in later YJ's, XJ/MJ's, TJ's, ZJ's and ( I think) WJ's.
 
ah and to add to the mess..I belive diamler stopped putting the 4.0 in their other jeep "wanna be" suvs this year. so our last and final hold out for the 4.0 is the current wranglers. good luck finding a donor.
CPl Maier
 
It is true that the 4.0 I6 has only ever been offered in Jeeps. The 4.0 is based on the old AMC 2.5 I4, basically with two extra cylinders added. To be specific the 4.0 was available in the 87-91 MJ, 87-01 XJ, 91-95 YJ, 93-98 ZJ, 99-04 WJ & 97-current TJ. So currently the 4.0 is only available in a TJ and the TJ is scheduled for a complete makeover in '07 at which time the 4.0 will be dropped for good, replaced throughout the Jeep lineup by the 3.7 V6. That will make for an even 20 years of 4.0 production, pretty amazing when you consider the old school technology in that engine and it will still be available in a new '06 TJ! I love the 4.0, but it is without a doubt the most antiquated engine available in the U.S., but in our case that's a good thing :)
 
2001XJeep said:
It is true that the 4.0 I6 has only ever been offered in Jeeps. The 4.0 is based on the old AMC 2.5 I4, basically with two extra cylinders added. To be specific the 4.0 was available in the 87-91 MJ, 87-01 XJ, 91-95 YJ, 93-98 ZJ, 99-04 WJ & 97-current TJ. So currently the 4.0 is only available in a TJ and the TJ is scheduled for a complete makeover in '07 at which time the 4.0 will be dropped for good, replaced throughout the Jeep lineup by the 3.7 V6. That will make for an even 20 years of 4.0 production, pretty amazing when you consider the old school technology in that engine and it will still be available in a new '06 TJ! I love the 4.0, but it is without a doubt the most antiquated engine available in the U.S., but in our case that's a good thing :)
More than 20 years...it's based off the 258cid that debuted some time in the early 60s, IIRC. 5-90 knows...
 
The 4.0 is very, very similar to the 258, and it is a common misconception that it is based on it, but in fact it is derived from the 2.5 I4. Either way, the 4.0 itself has only been in production since the '87 model year which technically started in '86. So if the '06 model year goes through spring '07 then I guess technically the 4.0 will have been made for 21 years.
 
2001XJeep said:
The 4.0 is very, very similar to the 258, and it is a common misconception that it is based on it, but in fact it is derived from the 2.5 I4. Either way, the 4.0 itself has only been in production since the '87 model year which technically started in '86. So if the '06 model year goes through spring '07 then I guess technically the 4.0 will have been made for 21 years.
Sorry, Mate -- you have it backward.

The 2.5-liter was developed from the 258 (4.2-liter), and the 4.0-liter was also developed from the 258. The 4.0-liter was absolutely NOT developed from the 2.5-liter.
 
OK...Thanks guys...I was just curious. I thought that I had read somewhere that it was used in some other applications (I am thinking it said International or in commercial applications). Read it a long time ago and can"t remember where I read it. Thanks for the info and I thought maybe I could find something in another vehicle that wasn't "Picked Apart". Don
 
The true beginnings of the 242, like all the great legends, are lost in the mists of Time...

Seriously, the AMC OHV I6 started with the 199 in, I believe, the early 1950's. It was later stroked slightly and became the 232, and was stroked again and reppeared as the 258 (in about 1971, IIRC.) In 1975, they came up with the "Wide Deck" 258 - which became the basis for the 242. The late 258 and all 242 heads will swap (but I'm wanting to think the late 258 used 7/16" head bolts - can't swear to it at the moment...)

The lineage of the 242 is over 50 years old, and I am informed that it is being discontinued for the 2005 model year (DaimlerBenz thinks it's more cost effective to replace the 4.0 with the 3.7V6, rather than recondition the 4.0 tooling... Go figure.)

Why DaimlerBenz wants to discontinue the 4.0/242, while Chevvy (at least) is bringing the I6 idea back (cf. Vortec 4200 I6) remains a mystery - but something tells me the Germans never really forgave us for winning WWII...

5-90 :lecture:
 
Didn't mean to start an argument about this, and I totally agree that the 242 is so similar to the 258 that it's design is obviously intertwined with it. How else can we explain stroking a 242 with 258 crank :) One thing we all agree on is the demise of the I6 will be a bad move for Jeep & DC, but it appears to be inevitable...

Here's a passage regarding the 4.0 I pulled off the net, let me know what you think,
"The 4.0L inline 6 (I6) engine was introduced in the Cherokee in the late 80s and in the YJ in 1991. The cylinder design is based on the changes made to the fuel injected 2.5L I4 engine. The block and cylinder head are cast iron. It uses 7 main bearings and hydraulic lifters. The HP and torque gains are substantial over the older carbureted 258, but the peaks come at higher RPM. The fuel injected engine performs much better in off-camber, bouncy, and steep situations. It also calibrates better for changes in altitude. Fuel economy is also improved."

I will say it's interesting that the 4.0 and 2.5 share pistons, oil pump, bearings, etc to not share a common origin...
 
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