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4.0 liter swap?

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Old Feb 2, 2016 | 05:57 PM
  #21  
Chuck-The-Ripper's Avatar
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I don't have any experience with the 3.6 but my 08 3.8 has 140k miles on it. Almost 100k of them from me. I'd say with my driving habits it's had a pretty rough life. I drive 100 mile round trip a day and run 80-90 most the drive on 35s and now 37s. Other than burning oil, a cam sensor, and a crank sensor, which were all easily found by the built in code reader and/or a superchips, I've had 0 engine problems. My last vehicle was a zr2 blazer with a 4.3 so I may not be the best view for performance but my 3.8 runs like a rape date. It eats 4.0s for breakfast. I've driven a few 3.6s, only 3.21 and 3.73 gearing, but compared to mine they did feel like turds. I definitely didn't feel the 80hp difference..
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Old Feb 2, 2016 | 06:16 PM
  #22  
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Originally Posted by Chuck-The-Ripper
I don't have any experience with the 3.6 but my 08 3.8 has 140k miles on it. Almost 100k of them from me. I'd say with my driving habits it's had a pretty rough life. I drive 100 mile round trip a day and run 80-90 most the drive on 35s and now 37s. Other than burning oil, a cam sensor, and a crank sensor, which were all easily found by the built in code reader and/or a superchips, I've had 0 engine problems. My last vehicle was a zr2 blazer with a 4.3 so I may not be the best view for performance but my 3.8 runs like a rape date. It eats 4.0s for breakfast. I've driven a few 3.6s, only 3.21 and 3.73 gearing, but compared to mine they did feel like turds. I definitely didn't feel the 80hp difference..
Interesting. I can't say I've heard anyone say they favored the 3.8l over the 3.6l. In driving both previously (mostly the 3.6l) I wouldn't own a 3.8l powered Wrangler. The 3.6l is the first somewhat sufficient engine in modern Wranglers.
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Old Feb 2, 2016 | 10:38 PM
  #23  
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Originally Posted by jedg
Is there that much lag? I had a 3.8 and so I know almost nothing about the 3.6 (though I guess I'll be learning since my wife is now driving a 2016 JK).

BTW, the LS conversions are drive by wire as well, but I'm sure the tune addresses any throttle lag.
its not that there is lag its just like other have said spotty and not consistant. if i push it about halfway down a few times you dont seem to get the same results each time. some will accel a little faster some timers a little slower ( same gear same road etc etc ) also every so often you seem to find a dead spot in the throttle response. Is it terrible? No but its not as linear / smooth as a throttle cable always was. I also dont like the through of havin a pedal sensor or a servo motor in the throttle body to worry about now.
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Old Feb 3, 2016 | 03:23 AM
  #24  
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Originally Posted by shabbernigdo
its not that there is lag its just like other have said spotty and not consistant. if i push it about halfway down a few times you dont seem to get the same results each time. some will accel a little faster some timers a little slower ( same gear same road etc etc ) also every so often you seem to find a dead spot in the throttle response. Is it terrible? No but its not as linear / smooth as a throttle cable always was. I also dont like the through of havin a pedal sensor or a servo motor in the throttle body to worry about now.
I don't know if it is a placebo fix, or it actually changes the feel of the fly by wire thing....Have you done the "gas pedal recalibration"? engine in on position, driving miss daisy slow, slowly depress gas pedal, and just as slow let it come back up.
turn off, then start, and drive away. I do this at least once a month and at least "I" can tell the difference. Passengers can't tell, but then again they can't tell the feel of the deadness in the gas pedal on takeoff. oh, 2014, manual trans, JKU, 75,000. (And black is the fastest color)
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Old Feb 3, 2016 | 03:59 AM
  #25  
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Originally Posted by shabbernigdo
its not that there is lag its just like other have said spotty and not consistant. if i push it about halfway down a few times you dont seem to get the same results each time. some will accel a little faster some timers a little slower ( same gear same road etc etc ) also every so often you seem to find a dead spot in the throttle response. Is it terrible? No but its not as linear / smooth as a throttle cable always was. I also dont like the through of havin a pedal sensor or a servo motor in the throttle body to worry about now.
Okay, gotcha. Yep, that would be annoying.
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Old Feb 3, 2016 | 07:01 PM
  #26  
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Originally Posted by dewey7015
I don't know if it is a placebo fix, or it actually changes the feel of the fly by wire thing....Have you done the "gas pedal recalibration"? engine in on position, driving miss daisy slow, slowly depress gas pedal, and just as slow let it come back up.
turn off, then start, and drive away. I do this at least once a month and at least "I" can tell the difference. Passengers can't tell, but then again they can't tell the feel of the deadness in the gas pedal on takeoff. oh, 2014, manual trans, JKU, 75,000. (And black is the fastest color)
No. i never even thought about any recalibration procedure for the throttle assembly. ill have to try that and see if it changes anything. ty
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Old Feb 5, 2016 | 01:00 PM
  #27  
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From: Highland, CA
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I avoided the 2012 JK just to miss all the first year problems. I have 2013 Rubicon. Never had a code, never feel it is unreliable or worry about it. I wheel it hard and often. Clutch forward or back, it works well. Several club members dumped their 3.8's just for the new engine. As for the 4.0 in the TJ or LJ, great engine for a lighter vehicle, wouldn't want it in my JK. With all the changes involved, go with the LS. Cookie cutter today and not the issues of the Hemi and over heating.
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Old Feb 20, 2016 | 11:36 AM
  #28  
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I actually saw a 4.0 build on another forum. The guy was from across the pond and replaced another engine with a stock 4.0. Believe his mpg was low 20s and drivability was better. Electronics though... That was a mess
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Old Feb 20, 2016 | 10:57 PM
  #29  
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Originally Posted by metaldemon
I think I am leaning toward getting a older Jeep. Hind sight is 20/20, and I really do wish I hadn't bought the JK. I thought I wanted a new vehicle, but I wasted my money. I should have bought an older one, and built a really good rig. Then I would have had money left over for another daily driver XJ. Anyone know of a nice YJ 6 cylinder 5 speed near PA.
I hear you. If I ever get rid of my JK, it's to buy a nice LJ, then pull as much as the electronics as possible and go with a v8 or a diesel.
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