4.0 2004 compared to 3.6 2022

[Lab1]

I would much rather have the inline 6 than the V6. It might not be efficient but it was a very reliable and easy to work on motor. Unfortunately EPA got in the way and now we are having to move on to other power plants and more complicated transmissions.

It's the way of the world.......

This ^ 100 percent!

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[mwilk012]

This ^ 100 percent!

Yea, just bring a few extra crankshaft sensors and a PCM with you, you'll be good to go.

 

[LarryB]

To echo some of the previous posts, the transmission really is mated up well to the 3.6. It always appears to be in the right gear for every situation. As for the 3.6, I did test drive the 2.0 turbo. While I found the turbo to be quite responsive, I just simply liked how the 3.6 drove. It has solid passing power and it never seems to be working all that hard.

 

[Lab1]

Yea, just bring a few extra crankshaft sensors and a PCM with you, you'll be good to go.

Literally never had this problem, and I owned 6 jeeps with the 4.0l from ‘97 - ‘06. I don’t count the YJs lol.

 

[mwilk012]

Literally never had this problem, and I owned 6 jeeps with the 4.0l from ‘97 - ‘06. I don’t count the YJs lol.

YJ's are turds.

I would estimate that those are the top two failure points of the 4.0 TJ's, at least with a busted radiator and exhaust manifold leak you can still drive it.

Also, 6 Jeeps in 9 years, what did you put 20k miles on each?

 

[Wolfy]

I traded a Ford Fusion Sport 2.7L Turbo V6 in for my Jeep Wrangler Sport S 2D 3.6L NA. I expected to see a huge lose in acceleration and pedal response, but I'm really just super impressed by the performance of the 3.6 with the 8sp auto. I also swapped the exhaust for a Borla S-Type. I don't think it made much, if any difference in performance, but sounds fantastic. In the end, I stomp on the pedal and this little 2-door jeep freakin' goes!

 

[Lab1]

YJ's are turds.

I would estimate that those are the top two failure points of the 4.0 TJ's, at least with a busted radiator and exhaust manifold leak you can still drive it.

Also, 6 Jeeps in 9 years, what did you put 20k miles on each?

I doubt I got to 20k on any of them lol! I was in my “prime” jeep days back then as were many of my friends. We traded them like baseball cards. A lot of us did this with CJs prior to this.

Definitely agree, YJs are turds but they also would weed out those that weren’t true jeep peeps. Have to admit, a 4.0l lifted YJ was a lot of fun just because of the pucker factor thanks to those leaf springs.

 

[Barely Krawlified]

Take it for what it’s worth (I’m not an engineer or a mechanic) but in general the JL/JLU Wrangler and specifically the 3.6/8 speed automatic transmission is just wonderful in this platform. The JL/JLU’s road manners (as others have pointed out) are just night and day better versus the TJ generation and while the 4.0 inline 6 was and always will be a fantastically bulletproof motor, the 3.6 PUG is every bit its equal in terms of reliability but in every way is more efficient and refined.

Although I’m likely not qualified to have any credibility on the subject other than my ownership of one I have no hesitation in asserting that the JL generation is quite simply a masterpiece from Jeep. Enjoy…

 

[JEEP4U]

I have manuals in both the TJ and JL. The 4.0L has more torque in low rpm. The 3.6L likes the higher rpm range. Gear accordingly with a manual trans.......the 8 speed auto is a little more forgiving...........Currently running 40's in the JL with 5:38 gear.

 

[Some Random Guy]

Had both myself. ‘92 XJ and ‘20 JL. The power output of the JL is way beyond the XJ in day to day. I’ve bounced it off the rev limiter multiple times on accident, even with all that extra weight. That NEVER happened with my XJ, it would just bog down and I’d notice more readily when it was winding up too much.
As stated, both are reliable. Granted, my college idiot self probably couldn’t work on the 3.6 as easily as he did the 4.0. But the suspension is easier.

 

[DaltonGang]

I had a 98 TJ 4.0 manual. It felt peppy at the time, but the biggest plus was the low end power. It felt very stable crawling at slow speeds. Very simple, and easy to work on, and would last. I had friends with the 4.0L and they went over 300k, without any major issues.

Now, my 2018 JLUS 3.6L Auto, is more of a hot rod, compared to the 4.0L.
it is big. It is stable. It is quick. It is overly complicated with glitchy electronics. I enjoy it now, but I'm not sure about the longevity of the entire JL package.
Ideally, I would like to see a TJ 4.0L, mated with the JL's 8speed auto tranny.
The best thing about my JL, is the Tranny, and the Alpine stereo system. The TJ stereo sucked, beyond belief.

 

[aldo98229]

These days EVERYTHING is loaded with electronics, even a $15,000 Kia.

The days of simplicity with no electronics are gone the way of carburetors and drum brakes.

 

[guarnibl]

I only have experience driving a 4.0 inline six cylinder motor in my 2004 wrangler unlimited . I ordered a 2022 unlimited willy's with a 3.6 auto trans . Looking to see if someone that has experience driving both motors . Wondering if the v6 will feel a little more powerful , or a lot more powerful over the inline 6 . The 4.0 always got it done , just checking to see if the gets it done quicker .

The 8 speed transmission makes the difference in the JL.

If you compared it to a JK 3.6, the 4.0 feels faster.

 

[deserteagle56]

I have manuals in both the TJ and JL. The 4.0L has more torque in low rpm. The 3.6L likes the higher rpm range. Gear accordingly with a manual trans.......the 8 speed auto is a little more forgiving...........Currently running 40's in the JL with 5:38 gear.

I had a 98 TJ 4.0 manual. It felt peppy at the time, but the biggest plus was the low end power. It felt very stable crawling at slow speeds. Very simple, and easy to work on, and would last. I had friends with the 4.0L and they went over 300k, without any major issues.

Now, my 2018 JLUS 3.6L Auto, is more of a hot rod, compared to the 4.0L.
it is big. It is stable. It is quick. It is overly complicated with glitchy electronics. I enjoy it now, but I'm not sure about the longevity of the entire JL package.
Ideally, I would like to see a TJ 4.0L, mated with the JL's 8speed auto tranny.
The best thing about my JL, is the Tranny, and the Alpine stereo system. The TJ stereo sucked, beyond belief.

^ This.
I've owned two TJs - still driving one of them. Manual trannies with the 4.0 straight 6. The low end grunt of the straight 6 is why some call this a "tractor engine". When I'm on trail rides with other Jeep buddies, the guys with the V6 engines are amazed that I can drive my Jeep over the rough stuff and never have to touch the throttle - that straight 6 just refuses to stall, even at engine idle speeds. Their V6 engines/manual trannies have to have some throttle or they stall. If you look at torque curves for both engines, sure, the V6 engines have both more horsepower and more torque. But those torque curves don't tell the whole story - they start at no lower than 1500 rpm. Hell, I drive for miles and the engine never gets up to 1500 rpm. There is no need.

This of course doesn't apply to the automatic tranny Jeeps - no worries about stalling. And yes, the V6 models are much nicer on a good road where rpms can be kept up. A lot more power. That old straight 6 flat runs out of steam at highway speeds, going up a steep grade or bucking a fierce head wind.

 

[Dkretden]

Ok , now the big one . Death wobble on newest models?

This board is full of extremely good info. issues of this and that, etc, as you would find on any enthusiast board like this…….. but to my eye, seemingly very few reports of death wobble on the JL.

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