Is the 3.8 really that bad?

Chadrobb

New member
So I've been reading four wheeler and they really don't seem to like the 3.8, making it sound like I am driving a bomb and the biggest piece of garbage ever built. But reading through these forums, I don't see that many issues? And they are literally everywhere here. Sure it's a minivan engine, my father in law put over 200k miles on his before he traded it. He changed the oil every 3k and that was it.

I maintain all my Jeeps myself, and I am new to the JK (2010). Any words of wisdom, key maintenance other than the norm?

I just don't get it. :idontknow:
 
really the only problem i have ever seen with the 3.8 is just that it is underpowered. that is why you see the stroked 3.8 article and people doing LS or hemi swaps that had a 3.8. other than that it seems like a very reliable engine.
 
How many issues have arised from RIPP's supercharger mod?
I'd rather do that then have my 3.8 rebuilt (at how much $$$) to gain just a few Hp.
I'll bet the rebuild and dyno-tuning of that 3.8 in the mag was more than $6k.
 
I'm the outlier on this, but I have a 2007 and my wife has a 2014. We both like the "powerband" of the 2007 more. Smoother, doesn't hang in 3rd as long. FWIW, hers is still in break in (700 mi) and they are both automatics.
 
How many issues have arised from RIPP's supercharger mod?

The only person I know personally that had one ended up yanking it out. It was nothing but a big headache. Performance and reliability aside, I think they sound like absolute crap.
 
The only person I know personally that had one ended up yanking it out. It was nothing but a big headache. Performance and reliability aside, I think they sound like absolute crap.

While it is true that I had no issues with the 3.8 OEM powerband while on the Rubicon last June, it was the travel to and from that was tedious.
$6K for a supercharger is even more tedious.

My wife likes the lack of power on the freeways, she says we see more of the scenery this way. :cheesy:
 
I certainly won't be stroking the 3.8, or worrying about it much. I'd rather put that kind of cash into axles. I'm just shocked at the number of mentions on that site in a lot of articles. So far so good for us, we love the JK.
 
So I've been reading four wheeler and they really don't seem to like the 3.8, making it sound like I am driving a bomb and the biggest piece of garbage ever built. But reading through these forums, I don't see that many issues? And they are literally everywhere here. Sure it's a minivan engine, my father in law put over 200k miles on his before he traded it. He changed the oil every 3k and that was it.

I maintain all my Jeeps myself, and I am new to the JK (2010). Any words of wisdom, key maintenance other than the norm?

I just don't get it. :idontknow:

I have a 2010, 105000 miles and so far so good...I do oil changes every 6k miles synthetic since I bought it new. I switched to high mileage synth at about 80k miles and that seems to have cut down the consumption.

I also service the transmission more than average because I tow and put a lot of miles on it. Probably not related but I think servicing the trans help keep the heat down overall as well.

only real issue I have is the lack of power and the power band being so high in the rpm range and the transmission ratio from 3rd to OD (which I feel causes too much gear hunting on slight inclines) because of that, I don't use OD when wheeling or if I'm driving with any incline. the less work the trans has to do the less work the engine has to do.

I have 4.88's running 35's and it does fine for most all my drives, I push it on the mountain passes but have started to slow down with the high mileage.
 
I have a 2010, 105000 miles and so far so good...I do oil changes every 6k miles synthetic since I bought it new. I switched to high mileage synth at about 80k miles and that seems to have cut down the consumption.

I also service the transmission more than average because I tow and put a lot of miles on it. Probably not related but I think servicing the trans help keep the heat down overall as well.

only real issue I have is the lack of power and the power band being so high in the rpm range and the transmission ratio from 3rd to OD (which I feel causes too much gear hunting on slight inclines) because of that, I don't use OD when wheeling or if I'm driving with any incline. the less work the trans has to do the less work the engine has to do.

I have 4.88's running 35's and it does fine for most all my drives, I push it on the mountain passes but have started to slow down with the high mileage.

Agreed jeeep... I have the same year as you (2010) and found it's better to be safe and baby this drivetrain for best performance.

I highly recommend to all JK owners what you've done as well with your gears... I too decided to go with 4.88 gears with 315/70R17's and it was a wise choice as many recommended going bigger to 5.13 or higher, but with the 3.8L lack of giddy-up, I was reluctant to go that high and has proven to be a good blend of initial get up and go, and good highway manners.

Kudos brother!
 
I have a 2010 JKU Sport auto that was on 33s and had been thinking about upgrading the stock axles with 4.88 gears and lockers. I had also considered getting Rubi axles with the 4.10 gears from a forum member. I then decided to wait a couple of years until I could upgrade to a Rubicon with the 3.6 engine and 5 speed auto. I have a superchip tuner and run the 87octane tune. Earlier this year I went to the dealership and drove a couple of the 2014 JKUs, a Rubicon with 4.10 gears and a non rubi with the same 3.7 gears that I was running. I really couldn't see a big difference in power from my 3.8. I suppose the 3.6 really does have more power, but seat of the pants it didn't feel like much at our nearly 5k altitude.

Recently another forum member listed his Rubi axles for sale with 5.13 gears and other upgrades. So I decided to stick with the 3.8, only 33k miles, and do the Rubi axle swap. I am really glad I did! I've completed the swap and increased the tire size to 35s and the gearing is perfect. Even with the larger tires the overdrive is more usable than it was with stock gears and tires. And I now have lockers front and rear. Waiting until I could buy a Rubicon would have involved starting all over again on my mods as well. There has been a fair amount of forum traffic about problems of one kind or another with the 3.6 and that was also a factor in my decision.

So I've spent quite a bit of time considering the pros and cons of the 3.8 and am really content with my decision to stick with it. It is too soon to tell how bad my mileage will be hurt by the lower gears and bigger tires, but as far as performance is concerned I believe I've got the perfect combination.
 
really the only problem i have ever seen with the 3.8 is just that it is underpowered. that is why you see the stroked 3.8 article and people doing LS or hemi swaps that had a 3.8. other than that it seems like a very reliable engine.



Reliable? Haaaa horrible gas mileage, minivan power, burns 1 quart of oil every 1k miles
 
So I've been reading four wheeler and they really don't seem to like the 3.8, making it sound like I am driving a bomb and the biggest piece of garbage ever built. But reading through these forums, I don't see that many issues? And they are literally everywhere here. Sure it's a minivan engine, my father in law put over 200k miles on his before he traded it. He changed the oil every 3k and that was it.

I maintain all my Jeeps myself, and I am new to the JK (2010). Any words of wisdom, key maintenance other than the norm?

I just don't get it. :idontknow:
I have found the 3.8 to be a very reliable motor the only downfall, as mentioned, is the lack of power. For me personally it isn't THAT big of a deal as I am not racing it or anything like that. With the proper gearing it performs quite well on the highway aswell. I've broken odd parts on trails (u joints, mild body damage) but I've never been stuck or broke down because of the engine or any of its components. So for me it's good!!!!
 
The 3.8 is a DOG plain and simple. You can make all the excuses in the world but the fact remains that it should have never been used as a jeep power plant.
 
I have a 2010 JKU Sport auto that was on 33s and had been thinking about upgrading the stock axles with 4.88 gears and lockers. I had also considered getting Rubi axles with the 4.10 gears from a forum member. I then decided to wait a couple of years until I could upgrade to a Rubicon with the 3.6 engine and 5 speed auto. I have a superchip tuner and run the 87octane tune. Earlier this year I went to the dealership and drove a couple of the 2014 JKUs, a Rubicon with 4.10 gears and a non rubi with the same 3.7 gears that I was running. I really couldn't see a big difference in power from my 3.8. I suppose the 3.6 really does have more power, but seat of the pants it didn't feel like much at our nearly 5k altitude.

Recently another forum member listed his Rubi axles for sale with 5.13 gears and other upgrades. So I decided to stick with the 3.8, only 33k miles, and do the Rubi axle swap. I am really glad I did! I've completed the swap and increased the tire size to 35s and the gearing is perfect. Even with the larger tires the overdrive is more usable than it was with stock gears and tires. And I now have lockers front and rear. Waiting until I could buy a Rubicon would have involved starting all over again on my mods as well. There has been a fair amount of forum traffic about problems of one kind or another with the 3.6 and that was also a factor in my decision.

So I've spent quite a bit of time considering the pros and cons of the 3.8 and am really content with my decision to stick with it. It is too soon to tell how bad my mileage will be hurt by the lower gears and bigger tires, but as far as performance is concerned I believe I've got the perfect combination.

Agree. I have a 08 JKU Rubicon with roughly 110k on it currently. Just this April I upgraded from 35s to 37s and with that went from my stock 4.10 Rubicon gears to 5.13s. Since the change I've put on roughly 9000 miles of city/highway driving with (regrettably) only one off road trip to ORV Park in Hot Springs Arkansas. It's also my opinion that upgrading the gears was well worth it and it shows in both its highway performance (remaining in overdrive on hill climbs) and off road performance (great crawl ratio).

All that being said, I'm still envious with anything that has more power, including the 3.6 pentastar. I think the 3.8 is underpowered for the JK, especially an Unlimited with larger tires. However, I've not had any issues with the engines reliability, knock on wood.

Bottom line, regearing is a must once you go larger tires.
 
In a head to head drag race of identically equipped JK's the 3.6 is significantly faster. However, drag racing isn't what the JK is all about. I've driven both and definitely like the 3.6 on the road. There's little difference once you leave the blacktop. There are some members of this forum who modded their JK's 'til they were 7,000lbs+ and got by for years. The downside is you have to spank the 3.8 pretty hard to get down (up) the highway and you cut its life a little short. The 3.6 can be found in Ram trucks, Dodge cars and Jeeps. I think it has stronger internals than the 3.8 and you can beat it up a little longer. Bottom line is the 3.8 isn't so bad at all as long as you're not weighing north of 7k lbs and not trying to turn 37's with 3.21 gears. I'm old school and for me the only real answer is a thundering American V-8. I get hate mail from the EPA.:twocents:
 
In a head to head drag race of identically equipped JK's the 3.6 is significantly faster. However, drag racing isn't what the JK is all about. I've driven both and definitely like the 3.6 on the road. There's little difference once you leave the blacktop. There are some members of this forum who modded their JK's 'til they were 7,000lbs+ and got by for years. The downside is you have to spank the 3.8 pretty hard to get down (up) the highway and you cut its life a little short. The 3.6 can be found in Ram trucks, Dodge cars and Jeeps. I think it has stronger internals than the 3.8 and you can beat it up a little longer. Bottom line is the 3.8 isn't so bad at all as long as you're not weighing north of 7k lbs and not trying to turn 37's with 3.21 gears. I'm old school and for me the only real answer is a thundering American V-8. I get hate mail from the EPA.:twocents:

I'm old school and I agree 100% that there is nothing like an AMERICAN V8. No substitute for cubic inches. By the way, the most RELIABLE engine ever made by any country is the Chevy small block V8. My C6 LS3 VETTE engine still has only 2 valves per cylinder and 1 cam but puts out 430hp and 400+ lbs of torque. At 70mph it is only turning 1500rpms.
 
I'm old school and I agree 100% that there is nothing like an AMERICAN V8. No substitute for cubic inches. By the way, the most RELIABLE engine ever made by any country is the Chevy small block V8. My C6 LS3 VETTE engine still has only 2 valves per cylinder and 1 cam but puts out 430hp and 400+ lbs of torque. At 70mph it is only turning 1500rpms.

You know what they say no replacement for displacement
 
Top Bottom