Just to sum it up: Some, but not all of the 2007 3.8 engine burn oil. They were assembled in Mexico, and installed the oil control rings upside down. This engine is lacking power. But if geared properly, let’s just say do O.K. They have a track record of longevity.

 

Longevity is important Old Dogger, I might feel like something was wrong if I had a vehicle that didn't use oil. lol I spotted that jk and slid over here to the dark side to see what others thought about it. I just want to have options. My bank won't release my funds for a few more days, so I'm trying to do my homework ahead of time.

 

I loved my TJ Sport 4.0 auto. Rode like a tank. Went everywhere I wanted. But the frame rotted away. Like a lot of them do from the rust belt. Now.....like said....the 3.8 is not a power house. But neither is the 4.0 in real life. Ya...better than the 2.5. I had one of those too. Great for around town....but 65mph.....no. Back to the 3.8 Never had one in the Wrangler....but dad had a minivan with one. LOL. It was ok. Like said...some will burn oil. The 3.8 does like to crack exhaust manifolds. So if you hear some noise. Time to replace them. The 2012 and newer 3.6 is more powerful but I think may have more problems than the 3.8! Good luck and welcome!

 

If your looking for longevity and reliability, you probably cant beat a 3.8. There is a reason Chrysler used it for 20 years in some of there most popular vehicles. Decent low end torque for that size. I have a 2010 JKU with the 6 sp and 3.73 gears on 35s. It is livable but not great. If that is a auto with 3.21 gears, there is just enough power in the 3.8 to overcome that anchor unless your running street tires.

 

If your looking for longevity and reliability, you probably cant beat a 3.8. There is a reason Chrysler used it for 20 years in some of there most popular vehicles. Decent low end torque for that size. I have a 2010 JKU with the 6 sp and 3.73 gears on 35s. It is livable but not great.

I didnt know you could get a 6sp with the 2010. Mine is a 2dr, 4 spd. Its a turtle. 373 gears is factory for a 2dr. Mine doesnt burn any oil. 😉

 

Yep, as above... Not a bad motor, some burn oil. But pretty reliable. Exhaust manifolds are prone to cracking. But the trans gear ratios they chose kind of sucked and didn't help the motor. If you want to go up on tire size, a re-gear is more important than ever.

 

I have a 6spd 3.21 geared 2011 3.8 with 33"s. Its liveable but not ideal by any stretch. It's basically a 5 spd. unless going downhill on the highway for a long stretch. She does burn some oil but otherwise it's a decent motor. IT seems to need new plugs every 40-50k.

 

I have 2007 JKU with 136k miles as a weekend toy. Engine and transmission still feel and sound new. Glad this one came with 4:10 gears. Does ok. Funny when driving around town, stomp on it and it revs and screams but doesn't really move any faster. Loaded on the highway, I can easily maintain 75 on hills, but you really need to convince it to drop out of overdrive. I now instinctively push the O/D off button every time I approach a hill. The only time I really had issues was in Colorado this past summer. I had it stuffed and heavily loaded. That first 20 or so miles north of Durango going up, I could barely maintain 45 mph and it started to get hot. Once I learned not to force the speed, the temp did fine. Did great on the trails.

 

I've owned mine since new. 175k miles later and I agree with the others. Reliable engine, a little underpowered and automatic transmission ratios suck.

 

The 3.8 is a great motor. Easy to tune, will handle a Supercharger just fine and overall high mileage engine. The 4 spd auto is poorly geared so regearing the diffs is a must and adding a throttle programmer will liven it up too. The 3.8 has a VERY lazy throttle program. I hope my current 3.6 lasts as long as my 08 3.8 is.


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The 3.8 is a great motor. Easy to tune, will handle a Supercharger just fine and overall high mileage engine. The 4 spd auto is poorly geared so regearing the diffs is a must and adding a throttle programmer will liven it up too. The 3.8 has a VERY lazy throttle program. I hope my current 3.6 lasts as long as my 08 3.8 is.

Yes, the older auto trannys were inefficient, and the DC programming was lazy. The new trannys are a lot more efficient. The same engine in the JL is a couple seconds faster 0-to-60 just because the new tranny is a lot more efficient.

Nothing wrong with the old engine. The old tranny and the old programming were the weak links.

 

It's a great motor very simple to work on. Like others have said keep an eye on the oil and it should serve you well. Re gear is a must if you plan to run anything bigger than pizza cutters with the 42RLE 4sp auto. I don't know much about the NSG370. Change the pcv valve once a year regardless if it needs it or not. Other than a total meltdown from a one and a million failure you should easily get 250 to 300k out of that powerplant.

 

Changing that PVC is tricky. The one time I tried, I cracked the plastic valve cover.

 

im sure you are aware but I feel like mentioning it. there is a lot more different than just the engine between a tj and a jk....completely different animal. having said that we had a 3.8 in a minivan and it was great. sold with 230k and running strong. I drove a few 3.8 JKU's before buying my 3.6 JKU. even with a stick shift still just didn't feel like enough for me, but that a JKU and my personal preference.

 

I have 90+k miles on my 2010 JKUR with the 3.8. Doesn’t seem to burn any oil. It has been a good engine so far. Underpowered for my built, heavy Jeep on 37s, but it does the job. You definitely will want to regear if you have even slightly oversized tires. I’m running 5.13s with 37s. Automatic transmission. Around town and on the trails it is fine. On the freeways, it definitely feels underpowered. But after seeing the majority of my friends with 3.6s have engine problems, I’m happy I have the 3.8.

 

So I'm looking to buy my first wrangler. I really want a TJ, but I ran across a 2007 2 door JK today.

What are you're thoughts on the 3.8?
I've heard mixed reviews from people. This particular one is at 177K miles. I'm use to dealing with the 4.0, so the 3.8 is uncharted territory for me.

I have a 2007 2dr JK X, 6 speed manual with 187000 miles and runs great, no oil leaks and burns maybe 1/2 quart every 3500 miles. They definately aren't going to win at the drag strip but if the maintenance was done consistantly and "good quality" parts, oil, filters were used along with just plain general maintenance, they'll last a long time. I have 33's on mine and it's much more a pavement jeep but do get to do a little off roading. (Nothing severe) At that milage it all comes down to how the previous owner(s) took care of it. Good luck, they are fun!!!!

 

My daughter’s 2010 is 2 door automatic. It’s the islander package so has 3.73 gears. Slightly oversized wrangler duratracts 255/R17 if I remember correctly. Slow on take off but enough power for a teenager in a 2 door. It does burn a little bit of oil. Bought at 99K miles, at 108K miles, engine runs good and strong, hope to get another 50K miles out of it, at least.

 

I went from a loved 4.0/6mt/3.73 LJ to a 3.8/AT/3.21 jku. I couldn't sell it fast enough! Power delivery was horrible, my 22re Yota had more giddyup. While reliability is important, I like to maintain Pole Position as often as possible! My 3.6/AT/3.73 JK has been a pleasure to own n operate since day one. FWIW

 

You do realize that a 3.8 JK with 3.21 gears would be the equivalent of your 3.6 JK with 2.75 gears right? The 3.8 JK needs 4.56 gears just to match the 3.6 with 3.73. It’s never been a power issue with the 3.8 it’s a gearing issue. 5.38 gears auto on 35s the 3.8 is a bullet. The 3.8 fly by wire throttle programming sucked as well. Once address it feels much more like the 3.6. Just like the JK 3.6 throttle program sucks compared to the JL 3.6 throttle


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Mine is an 2011, AT with 3.73 on 35s and it is a turtle. Dont understand what they were thinking...

 

I'm happy with my 3.8. Strongly reccomend jscan app to reset tyres size to larger than actual size. This makes the auto shift at far better times and the egr/eco mode far more decisive. Also has a dramatic affect on throttle lag and low end torque delivery.

I run mine on Castrol Edge 10w-60. Never burns a drop. Quiet and smooth.

 

So I'm looking to buy my first wrangler. I really want a TJ, but I ran across a 2007 2 door JK today.

What are you're thoughts on the 3.8?
I've heard mixed reviews from people. This particular one is at 177K miles. I'm use to dealing with the 4.0, so the 3.8 is uncharted territory for me.

hold out for a TJ much better jeep

 

Bought our 2010 JKUR new. Have 175,000 miles on her now. Burns about a quart every 3,000 miles or so and just replaced the exhaust manifolds. Other than that no issues.

I change the oil every 5,000 miles with Mobil 1 and change the transmission oil, transfer case and diffs every 50,000 miles.

It's slow but I'm ok with it.