3.6L "Hiccup"

Truckn

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Hey All,

First off, I love this Jeep! I'm coming from a 2019 Camaro ZL1 1LE and I thought I was going to miss the power and handling but I don't -- I'm too busy enjoying the high driving view, utilitarian feel, and infinite customization -- it just feels more me.

I'm experiencing two things that may be unrelated.

#1. Hesitation / "Hiccup" often while maintaining speed or light acceleration around 3rd gear & 3k. It feels like a 1/4 second cut in power. It's not super jarring, if you were not driving you'd just think we drove over a tiny bump in the road but you can feel it. It is pretty random, not just when the engine is cold -- it happens when cold and at full operating temp.

#2. Slightly rougher than expected idle? This may just be a characteristic of the engine that I need to get used to but it feels to me like the entire car vibrates a mild-but-noticeable amount when idling. Idle appears to be about 700rpm give or take.

I have about 1200 miles on the clock, 100% stock and thoughtful brake-in.
It's a manual transmission, no real load, just me and my wife and daughter.
I live in California and the weather has been clear and mid-50s.
I've been putting 91 octane in it only because I'm still at low mileage, i'll probably switch to 87 soon.

I'd appreciate any insight from you experienced Pentastar 3.6L owners.

Thanks for your help!





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OldGuyNewJeep

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Hey All,

First off, I love this Jeep! I'm coming from a 2019 Camaro ZL1 1LE and I thought I was going to miss the power and handling but I don't -- I'm too busy enjoying the high driving view, utilitarian feel, and infinite customization -- it just feels more me.

I'm experiencing two things that may be unrelated.

#1. Hesitation / "Hiccup" often while maintaining speed or light acceleration around 3rd gear & 3k. It feels like a 1/4 second cut in power. It's not super jarring, if you were not driving you'd just think we drove over a tiny bump in the road but you can feel it. It is pretty random, not just when the engine is cold -- it happens when cold and at full operating temp.

#2. Slightly rougher than expected idle? This may just be a characteristic of the engine that I need to get used to but it feels to me like the entire car vibrates a mild-but-noticeable amount when idling. Idle appears to be about 700rpm give or take.

I have about 1200 miles on the clock, 100% stock and thoughtful brake-in.
It's a manual transmission, no real load, just me and my wife and daughter.
I live in California and the weather has been clear and mid-50s.
I've been putting 91 octane in it only because I'm still at low mileage, i'll probably switch to 87 soon.

I'd appreciate any insight from you experienced Pentastar 3.6L owners.

Thanks for your help!
Do you have a manual trans? If so, the “hiccup” may very well be your clutch slipping. There’s a recall for that - dealer will bleed the cylinder and install a protective sleeve around the line to prevent it from wearing through. Don’t hesitate on this one, as severe damage can result if left unfixed.

If you have an auto, then I have no idea.

TSB 18-092-19 should address rough idle.
 

Pappy06

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Take a look at your rpm when it’s happening. If your throttle input is same and rpm climb momentarily = clutch slipping

If rpm falls = engine . Just info for your dealer.
 

Xcoaste

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I had the 3.6 in my JK manual and now I have the 3.6 in my JL but auto. The auto variation feels more refined , but there is an 8 year difference in the 2 engines. My 3.6 manual purred like a kitten at idle. Not to make an excuse for Jeep, but maybe you are just used to your previous vehicle?

Either way, I would address it with your dealer. The inconvenience of taking it in, will be worth it to settle your mindset, even if they don't find anything. That is what is great about a new car warranty!
 

Karnak

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Check your fuse box and make sure they're all pressed. could be something as trivial as a Fuse not seated properly and not making connection properly and with road/engine vibrations it glitches. Some people reported fixes from fuse checks. I just did mine to make sure I did NOT have any issues first hand so I can't comment if it works, but its been mentionned in other treads in relation to electronic issue etc.
 

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My 3.6 A/T 2018 runs well and has excellent pickup and no hesitation, I rarely see 8th gear but I did not regear when I did my lift and tires
 

Elsinore73

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What fuel are you running? I have noticed it’s rougher at idle on 87 octane than it is with 93, noticeably so. No pinging but certainly idles a little rougher with lower octane. I went back and fourth feeling a difference. Just running 93 now. I have a 3.6L manual trans
 
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Truckn

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Thanks everyone for the input. I will check with the dealer, you never know but in my experience they won't help you unless you can reproduce the issue consistently or it's just broken.

Fuse box check is a good tip, thank you!

I found this thread, sounds similar to me:
http://www.ausjeepoffroad.com/forum/showthread.php?t=151736

So far it hasn't been a serious issue, just an annoyance, I'm okay with waiting to see if it gets worse or goes away. I was just hoping to hear from one of you saying "This happened to me and here's how you fix it" ;)

Thanks all!
 

Nc138

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Yes - I notice the same 1/4 second "skip", at around 3k RPM. I will try to take a video as well. I think you hear it with the engine more than feel it. It may have to do with the e-torque as I believe it does help to slow the engine down for shifts, but the engine is not shifting during this time, could be a "bug".

I'm running 87 and see no issues with performance or rough idle.
 

Gorilla57

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It may have to do with the e-torque as I believe it does help to slow the engine down for shifts, but the engine is not shifting during this time, could be a "bug".
The OP has a manual transmission, so no etorque setup.
 

Kyanche

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My 3.6 (auto) vibrates at idle, I usually run mobil 87 gas, sometimes shell. It's been doing that since the day I brought it home. I did notice mine idles a little bit smoother in neutral.

It's a strong enough vibration that if I'm carrying cups of soda with ice in them, the ice will rattle in the cup lol. If nobody's sitting in the passenger seat I can see it jiggle.

I figured it might be motor mounts or something but I've had the hood up with the engine running before and haven't really seen anything that'd indicate a problem. Meh. Will get it checked out once things get healthier outside lol. Maybe our motors were made on a Friday.
 
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Yes - I notice the same 1/4 second "skip", at around 3k RPM. I will try to take a video as well. I think you hear it with the engine more than feel it. It may have to do with the e-torque as I believe it does help to slow the engine down for shifts, but the engine is not shifting during this time, could be a "bug".

I'm running 87 and see no issues with performance or rough idle.
Interesting that you're experiencing it with an automatic and I am experiencing it with a manual.
My gut tells me its either software trying to do something silly or a sudden random drop in fuel pressure. More likely software. I am going to try turning traction control off and see what happens, maybe you could try too.
 
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My 3.6 (auto) vibrates at idle, I usually run mobil 87 gas, sometimes shell. It's been doing that since the day I brought it home. I did notice mine idles a little bit smoother in neutral.

It's a strong enough vibration that if I'm carrying cups of soda with ice in them, the ice will rattle in the cup lol. If nobody's sitting in the passenger seat I can see it jiggle.

I figured it might be motor mounts or something but I've had the hood up with the engine running before and haven't really seen anything that'd indicate a problem. Meh. Will get it checked out once things get healthier outside lol. Maybe our motors were made on a Friday.
Your vibration sounds exactly like mine. Maybe it's nothing -- probably just built on a Friday hahaha

How many miles do you have on yours now? I'm wondering if its something that may still go away...
 

Punknhed

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6speed here, mine does the same hiccup. did it since it was new. did the clutch recall unfortunately the dealer said it passed the "stall test" even though i asked them to drive the damn thing and feel it slipping. The clutch sucks in this thing. Dealer says nothing wrong with it. IM eventually going to get tired of it put a centerforce or something stronger and better in it. i have almost 40k on mine btw.
 

Kyanche

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Your vibration sounds exactly like mine. Maybe it's nothing -- probably just built on a Friday hahaha

How many miles do you have on yours now? I'm wondering if its something that may still go away...
Mine has about 4100 miles on it now. I've had my JL Unlimited Rubicon about 15 months. I haven't really been driving much because of working from home and no traveling right now. On the plus side, with so little driving, I do enjoy every minute of it very much!

I mentioned the vibration at idle a few times around here before and a lot of people have said that they do not experience the same thing, so I don't think it's normal. Certainly the 3.6 in my JK didn't vibrate like that. Or the 3.6 in our 300. They're usually really smooth motors.

It's not like I've seen any signs of unwellness or misfires or anything either. Everything looks tip-top. Hrmm I suppose I could plug my bluetooth OBD scanner into it and see if it has any codes, but no check engine light or anything of that sort.
 

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