Sponsored

3.6L with 6 speed MT has uneven power band

Seanmh72

Active Member
Joined
Dec 9, 2017
Threads
9
Messages
31
Reaction score
17
Location
SoCal
Vehicle(s)
2018 JLU Sahara
Have a 2018 with about 8K on it. Have been having issues with an uneven power band while accelerating. I can feel it most when getting into 2nd from a turn around a corner. What I feel is that I turn with the clutch in and no gas. While letting the clutch out and giving the JL gas, I basically have no power. After about 1-2 seconds, then I can feel the power kick in and I am able to accelerate. Also, while accelerating getting onto the freeway, I can feel sluggishness.

Took it to the dealer yesterday and of course the response was that the tech could find nothing wrong with my JL.

Just really makes it not so much fun to drive.

Wondering if anyone else is experiencing something similar.
Sponsored

 

OldGuyNewJeep

Well-Known Member
First Name
Don
Joined
Sep 21, 2017
Threads
85
Messages
3,816
Reaction score
6,828
Location
CT
Vehicle(s)
2018 Wrangler JL, 2016 Yukon XL
Have a 2018 with about 8K on it. Have been having issues with an uneven power band while accelerating. I can feel it most when getting into 2nd from a turn around a corner. What I feel is that I turn with the clutch in and no gas. While letting the clutch out and giving the JL gas, I basically have no power. After about 1-2 seconds, then I can feel the power kick in and I am able to accelerate. Also, while accelerating getting onto the freeway, I can feel sluggishness.

Took it to the dealer yesterday and of course the response was that the tech could find nothing wrong with my JL.

Just really makes it not so much fun to drive.

Wondering if anyone else is experiencing something similar.
What speed and RPM when ā€œturning a corner with clutch in ... and letting out clutch?ā€ Are you blipping the throttle to rev match, or going so slow that letting out the clutch doesnā€™t cause it to slip (and therefore probably lugging)?

For getting on highway, there absolutely should be no sluggishness unless you are shifting way too early. Remember that youā€™re in an off-road vehicle that likes high RPMs. Donā€™t shift until 3-4K RPM if youā€™re trying to accelerate quickly.

22,000 miles on my 6sp and have no sluggishness whatsoever. Mineā€™s a Rubi, so 1st is very short and 5th and 6th are very tall, but theyā€™re working as designed. On sharp corners Iā€™ll rev match 2nd @30MPH and ~3K RPM, then use engine braking in combination with the brake pedal to slow down enough to safely make the turn. Once through it Iā€™m back on the gas and then up to 3rd. On wider turns 3rd is usually just fine, and Iā€™ll have completed my downshift before even entering the turn (i.e. no clutch work while turning, just brakes and gas). No lugging in either scenario for me.

Try this: from a dead stop, wind 1st out to 3.5K RPM and then get on the gas after shifting to 2nd. You should have zero sluggishness when you get on the gas after your shift. If you do, take it back in and make the tech drive with you.
 
Last edited:

Johnbuz

Well-Known Member
First Name
John
Joined
Oct 24, 2017
Threads
4
Messages
108
Reaction score
90
Location
Pittsburgh
Vehicle(s)
Subaru Tribeca
The RPM info requsted above is needed. I expect the OP expects the JLU to have more low end torque. I also did expect it to have the low end torque like my Ram 1500 4.7 and old Cherokee 4.0. Those old engines had plenty of torque between 1500 and 2000 RPM. Gotta drive the JLU differently.
 

anotherWS6

Banned
Banned
Banned
First Name
Jebadiah
Joined
Nov 19, 2018
Threads
23
Messages
255
Reaction score
167
Location
Mohegan Lake, NY
Vehicle(s)
2018 JL Unlimited
Sux, but you gotta rev these things.
 

Sponsored

tonythehomie

Well-Known Member
First Name
Tony
Joined
Oct 11, 2018
Threads
5
Messages
97
Reaction score
46
Location
Connecticut
Vehicle(s)
JL Wrangler Sport S (manual / 2 door / firecracker red)
Mine MT drives the same. I am coming from a coupe with an MT and just assumed thatā€™s how it drives.

Would be interested in hearing anyone with a manual transmission who is not experiencing this.
 

Peanut Butter

Well-Known Member
First Name
Pat
Joined
Mar 4, 2018
Threads
4
Messages
170
Reaction score
264
Location
Boise, ID
Vehicle(s)
JL?
Iā€™ve never driven a manual transmission, anything, that had an even power-band.

I have 37s and stock Rubi gears. Sluggish below 2k rpm. Revs very quick after that. Surprisingly quick for a 6 cyl jeep.

Gutless below 1500 rpm.

If What youā€™re describing is.. In second gear taking a turn at ~5mph without clutch, hit gas, slow to go then takes-off like a scolded dog (maybe even a little jerk/buck initially).... Sounds normal to me.
 

flot

Well-Known Member
Joined
Dec 17, 2018
Threads
15
Messages
187
Reaction score
250
Location
South Florida
Vehicle(s)
2022 JLU 392
I've been holding off to order a 2020, and last month I rented a JLU Automatic for a few days and really enjoyed the drive. A week later, I got the local dealer to give me a 6 speed manual as a loaner while my truck was in the shop.

I have to say - I was pretty disappointed with the manual transmission paired with the 3.6. Torque below 1500 rpm felt nonexistent and it probably wasn't until the 3rd day of driving that I felt really comfortable with it and I was really winding that motor up to get decent acceleration. And definitely had those moments when I thought 2nd gear was the place to be but found that I was pressing the accelerator to the floor and not going anywhere fast.

To me, what the OP describes sounds pretty similar to my experience. Test drive a 6 speed off the lot and see if you feel a notable difference from your JL.
 

OldGuyNewJeep

Well-Known Member
First Name
Don
Joined
Sep 21, 2017
Threads
85
Messages
3,816
Reaction score
6,828
Location
CT
Vehicle(s)
2018 Wrangler JL, 2016 Yukon XL
Mine MT drives the same. I am coming from a coupe with an MT and just assumed thatā€™s how it drives.

Would be interested in hearing anyone with a manual transmission who is not experiencing this.
You already have. :) See my reply, above. Youā€™re driving a Wrangler, not a coupe. Apples and watermelons.
 

Sponsored

anotherWS6

Banned
Banned
Banned
First Name
Jebadiah
Joined
Nov 19, 2018
Threads
23
Messages
255
Reaction score
167
Location
Mohegan Lake, NY
Vehicle(s)
2018 JL Unlimited
I've been holding off to order a 2020, and last month I rented a JLU Automatic for a few days and really enjoyed the drive. A week later, I got the local dealer to give me a 6 speed manual as a loaner while my truck was in the shop.

I have to say - I was pretty disappointed with the manual transmission paired with the 3.6. Torque below 1500 rpm felt nonexistent and it probably wasn't until the 3rd day of driving that I felt really comfortable with it and I was really winding that motor up to get decent acceleration. And definitely had those moments when I thought 2nd gear was the place to be but found that I was pressing the accelerator to the floor and not going anywhere fast.

To me, what the OP describes sounds pretty similar to my experience. Test drive a 6 speed off the lot and see if you feel a notable difference from your JL.
In a similar boat, I had a rental JK that was auto right before I bought my JL and liked it. It wasnt fast but it was OK. I dont remember how many gears that auto was - I think 6? Anyway, one of the main factors in getting my Jeep was that it was available with a manual trans as I really dislike auto's and am usually constantly shifting them manually. I took a quick test drive in a manual and dont remember thinking that it was super slow, but I have to say that the one that I bought certainly is. I was probably nervous during my test drive because despite having driven manual cars for over 20 years I was awful at it during the test drive and embarrassed by it with the salesman sitting next to me.

I too am very disappointed in this drivetrain combo and the lack of torque. And I also find myself sticking the gas pedal to the floor and having absolutely nothing happen. I have been thinking of asking to test drive another, new manual Jeep to see if something is wrong with my mine. Like, can it really be this bad? But I'm pretty sure tat's just how it is. And it will accelerate decently if I wind the motor out more. But something in me makes me want to shift at around 2,500rpm all of the time. It just feels like I'm driving like an A-hole when I spin it faster. I feel like a dumb teenager fng around with a car or that I dont know what I'm doing when I shift close to 4 grand during normal driving. But that's basically what I need to do to get decent acceleration.

And the highway.....OMG. I keep my front doors off and got a set of those foot rest thingies that go in the bottom hinge so you can cruise with your leg out of the Jeep. I love doing it but after the newness wore off I basically stopped because it gets frustrating. I have to shift so often on the highway that it just gets annoying having to pull my leg in and out, in and out, in and out. I live in NYS and the vast majority of the highways I drive on are hilly. Nothing crazy, but there just isnt much flat land around me. So while cruising at 65mph in 5th is OK when the road is going downhill or flat, as soon as it starts going uphill even a little the "this thing has no power monster rears its head. I give it more and more gas but keep slowly losing speed and even flooring it is often not enough to maintain 65 so I pop it into 4th. And if traffic flow is slower and I'm doing say 55mph I often use 3rd. Third gear on the highway. Ridiculous. So my left leg doesnt get to hang out on the foot peg anymore.

When you look at the gear ratios inside the trans these things have what SHOULD be considered a granny gear for 1st. I remember several older 4 speed pickups that family members had back in the day where you almost never used 1st gear and the 1st gear ratio is about the same as this new Jeep. But 1st in those trucks was good for about 10mph or so. I'm guessing. While 1st in this Jeep is good for what? Like 35mph off the top of my head? The point is that between the 3.45 axle ratio and the 32 inch tall tires these things are waaaaay under geared. The 4.10 that comes with the Rubicon should be the smallest gear available on any model IMO. It's about matching the gearing with the engine and its power production characteristics. The 3.08 rear in my big block Suburban works great. The 3 speed turbo 400 trans is just fine, I'm never wanting for more power. But that's got a ton of low rpm torque. This 3.6 needs all the help it can get so 6 gears are great, right? But the reality is that combined with the tall tires and fairly small axle ratio 5th is too tall and 6th is worthless. I can literally count how many times I've had my Jeep in 6th with just the fingers on my hands - maybe at the end of this lease I'll need to use my toes to count as well - maybe. And I swear I'm not exaggerating when I say that I now frequently just keep it in 4th on the highway when I have cruise control set to 64mph or slower. Am I crazy? Am I wasting gas? No. Because when you're going 60mph the overall gear ratio in 4th is what is correct. Its turning a little over 2,000rpm. I think 70mph in 4th is only about 2,500. And I keep my little dash digital screen on the instant MPG setting and look at it constantly. When the road flattens out for a stretch it will settle on low 20's in 4th. Shifting into 5th has never improved this on flat road. I'm a obsessive nut with sort of "testing".

And holy crap, I appear to be writing a boring novel here.

Today's modern, non turbo engines produce impressive HP figures but do so at the expense of low end torque. So OP - your Jeep is doe shave an uneven powerband. Every engine in the world does. There is always a sweet spot RPM-wise. Unfortunately in these Jeeps that sweet spot is higher than most of us are used to. I could go on a loooooooooooooooooooong rant about why. I'll spare you for now, however it has to do with fuel economy and the testing methods used. There is a huge financial incentice (penalty) for the auto manufacturers to improve fuel econmoy. The target figures are set by the governent. Automakers seek to improve the their MPG numbers IN TESTING. TESTING. This often does not translate over well to real world driving, but the government doesnt look at real world driving or care about your driving experience. They care about what a vehicle does in MPG TESTING. Look into it, it's F'd up. So we end up with drivetrain combos that suck.

I started daily driving what was my wifes DD awhile back and did so for about a year. It was a 2010 Cadillac CTS wagon. Absolutely beautiful car. Pearl white, big chrome wheels, gorgeous interior with tan leather. It rode and handled fantastic. Not a sports car but the overall combo was great. I wanted to love that car. Part of me did. It caught my eye sitting all polished up ready to go from a quarter mile away the day we picked it up. But I hated it. Why? It had a direct injected 3.6 liter V6 that made 300hp, a 6 speed auto and was slower than donkey shit. Zero low end torque. Continually had to floor it just to go. The power made it miserable to drive and I kept the trans in manual mode because otherwise it would go into 6th gear on the highway and then not move. I got into an accident with it and replaced it with my Jeep. My 3.6 liter V6 Jeep that is also slower than donkey shit.
 

Mane

Well-Known Member
Joined
May 23, 2019
Threads
5
Messages
81
Reaction score
106
Location
St. Pete FL
Vehicle(s)
4Runner LTD
What speed and RPM when ā€œturning a corner with clutch in ... and letting out clutch?ā€ Are you blipping the throttle to rev match, or going so slow that letting out the clutch doesnā€™t cause it to slip (and therefore probably lugging)?

For getting on highway, there absolutely should be no sluggishness unless you are shifting way too early. Remember that youā€™re in an off-road vehicle that likes high RPMs. Donā€™t shift until 3-4K RPM if youā€™re trying to accelerate quickly.

22,000 miles on my 6sp and have no sluggishness whatsoever. Mineā€™s a Rubi, so 1st is very short and 5th and 6th are very tall, but theyā€™re working as designed. On sharp corners Iā€™ll rev match 2nd @30MPH and ~3K RPM, then use engine braking in combination with the brake pedal to slow down enough to safely make the turn. Once through it Iā€™m back on the gas and then up to 3rd. On wider turns 3rd is usually just fine, and Iā€™ll have completed my downshift before even entering the turn (i.e. no clutch work while turning, just brakes and gas). No lugging in either scenario for me.

Try this: from a dead stop, wind 1st out to 3.5K RPM and then get on the gas after shifting to 2nd. You should have zero sluggishness when you get on the gas after your shift. If you do, take it back in and make the tech drive with you.
This sounds about right to me. These engines like a few extra RPMs, and really it's not a bad thing so much as just a characteristic of the engine. Once you get the hang of how they work, and the clutch breaks in, they are pretty enjoyable to drive.
 

Jeepcity

Banned
Banned
Banned
First Name
Ron
Joined
Feb 13, 2018
Threads
2
Messages
90
Reaction score
120
Location
BC
Vehicle(s)
jl rubicon tj rubicon yj cj 8 cj 7 cherokee
They may be fine on road after the fixes , but extreme off road ,not so much . But it seems hardly anyone uses them for that any more .
 

rid34fun

Active Member
First Name
Kurt
Joined
Aug 5, 2019
Threads
1
Messages
35
Reaction score
31
Location
Northern IL
Vehicle(s)
Yamaha Super Tenere
Occupation
Director of Campus Development
I have a new 2019 with the 3.6 and manual. I don't expect a 3.6 engine to have much torque at 1500 to 2000 rpm's. I have ridden motorcycles all my life and smaller engines in heavy vehicles need a few more rpm's. I am used to the engine power band and gears after 1500 miles. I took one hwy trip for a couple of hundred miles and agree a little that hills present a challenge depending on posted/actual speed. But, 5th gear handled almost anything in the midwest::) It is geared for EPA mileage, which I got a little over 25 at 72 mph on my short trip. I'll take it.

I also had a rental for some dealer items and had the 8 speed for a couple days. Nice trans, but I watched the rpm's and it down shifts alot on the hwy. A little easier to drive because you don't need to be engaged, but the engine still needs rpm's to move the JLU at the slightest incline. I still prefer my manual because I feel a connection to the vehicle.
Sponsored

 
 



Top