Sponsored

3.6L "Hiccup"

redracer

Well-Known Member
First Name
Robert
Joined
Aug 22, 2017
Threads
20
Messages
558
Reaction score
619
Location
Manteca, CA
Vehicle(s)
2023 4xe Rubicon
just found this thread, and have the same hiccup thing - reproducible at the same spot in my daily drive in 3rd or 4th gear at 45-50mph (I have the 3.6 non-e-torque with MT)

curious if anyone with this problem has also noticed severe exhaust smell when putting the engine under heavier loads (e.g. climbing long steady hill on highway) in 3rd and 4th gears? wondering if these are related. it's almost a clutch burning smell (under high loads, not the hiccup) but there is no noticeable increase in rpm at a steady speed (50-65mph).
Yes. I have a very noticeable exhaust smell under heavy loads or acceleration. And only at probably 35 mph or more. But only with the rear windows out or top down. This allows the exhaust to circulate into the cabin.

I believe this is due to the enrichment that happens at higher RPMs, just above our hesitation or "hiccup" in the power band, and at higher load. If you go dig up the threads about the 3.6 torque curves and the threads about aftermarket programming, they talk about the enrichment a bit .

I don't believe that this is a problem per say... It's just something that we are in a unique position to notice.
Sponsored

 

redelses

Well-Known Member
Joined
May 29, 2018
Threads
22
Messages
286
Reaction score
236
Location
St George UT
Vehicle(s)
2023 JLUR
thanks both!! it is definitely worse with back windows out, less so with top down, and barely noticeable when fully closed; and always above 35-40mph (usually in the highway speeds). I have brought it to the dealer claiming the clutch smell, because I really didn't think the exhaust would be that bad (smells more like oil than gas burning), and it takes about 5-10 seconds after the heavy load to hit and then only lasts a few seconds.

not happy that it happens, but happy to hear that others have noticed it as well and is likely (hopefully) just the exhaust in the higher rpm range under load.

thanks!!




Yes. I have a very noticeable exhaust smell under heavy loads or acceleration. And only at probably 35 mph or more. But only with the rear windows out or top down. This allows the exhaust to circulate into the cabin.

I believe this is due to the enrichment that happens at higher RPMs, just above our hesitation or "hiccup" in the power band, and at higher load. If you go dig up the threads about the 3.6 torque curves and the threads about aftermarket programming, they talk about the enrichment a bit .

I don't believe that this is a problem per say... It's just something that we are in a unique position to notice.

Some of that exhaust smell has much do do with the air flow around a boxy Jeep, especially with the top down where the air moves forward from the rear to fill in the low pressure area created behind the windshield in the passenger compartment. The flat and almost straight up windshield exacerbates it. Every Wrangler I've owned exhibits this no matter the year or engine.
 

Moosebear

Active Member
First Name
Moose
Joined
Jul 17, 2021
Threads
2
Messages
40
Reaction score
98
Location
HI
Vehicle(s)
21 JLUR, 84 Chevy M1008, 22 Axial SCX6
New JLUR with < 10k miles, 2.6 and 6 speed. It's done this since day 1. Nothing seems to make it better or worse but it happens almost every time at 43mph...
 

DavidArmen

Well-Known Member
First Name
David
Joined
Sep 19, 2020
Threads
28
Messages
1,468
Reaction score
1,616
Location
Los Angeles, CA
Vehicle(s)
2021 JLUR
My 2021 3.6 auto also vibrates at idle when the jeep is stationary, but only when the jeep is in four wheel drive. Itā€™s perfectly smooth in two wheel drive but as soon as itā€™s in four wheel drive and I come to a stop, the whole jeep vibrates noticeably the whole time itā€™s stationary (and transmission is in Drive).
 

DanW

Well-Known Member
First Name
Dan
Joined
Mar 2, 2017
Threads
159
Messages
8,404
Reaction score
11,073
Location
Indiana
Vehicle(s)
21 JLUR, 18JLUR, 08JKUR, 15 Renegade, 04 WJ
Vehicle Showcase
2
My 2021 3.6 auto also vibrates at idle when the jeep is stationary, but only when the jeep is in four wheel drive. Itā€™s perfectly smooth in two wheel drive but as soon as itā€™s in four wheel drive and I come to a stop, the whole jeep vibrates noticeably the whole time itā€™s stationary (and transmission is in Drive).
I'd have the transfer case checked. Sounds like something may be out of balance within it or maybe at the U-joints or couplings.
 

Sponsored

wolf

Well-Known Member
First Name
Rick
Joined
Oct 17, 2018
Threads
38
Messages
849
Reaction score
885
Location
florida
Vehicle(s)
On my third Rubicon(2dr's 2020, 2015 jetta diesel/2013 mb
Occupation
retired
Donā€™t laugh but years ago I had a grand Cherokee couple thousand miles or whatever doing the same thing turned out to be a plugged catalytic converter replaced the converter everything was fine.
 

JeepCares

Well-Known Member
Joined
Feb 1, 2018
Threads
15
Messages
5,092
Reaction score
2,568
Location
Auburn Hills, MI
Vehicle(s)
JL
just found this thread, and have the same hiccup thing - reproducible at the same spot in my daily drive in 3rd or 4th gear at 45-50mph (I have the 3.6 non-e-torque with MT)

curious if anyone with this problem has also noticed severe exhaust smell when putting the engine under heavier loads (e.g. climbing long steady hill on highway) in 3rd and 4th gears? wondering if these are related. it's almost a clutch burning smell (under high loads, not the hiccup) but there is no noticeable increase in rpm at a steady speed (50-65mph).
Hi, redelses. Although you're seeking the support of fellow forum members, we would also recommend a dealer visit. If decide to go that route and need our support, send us a private message.

Kate
Jeep Cares
 

T.T.T

Well-Known Member
First Name
Ty
Joined
Apr 23, 2019
Threads
10
Messages
62
Reaction score
13
Location
South Carolina
Vehicle(s)
ā€˜18 Jl 6spd, ā€˜01 Tj Sahara 5spd
just found this thread, and have the same hiccup thing - reproducible at the same spot in my daily drive in 3rd or 4th gear at 45-50mph (I have the 3.6 non-e-torque with MT)

curious if anyone with this problem has also noticed severe exhaust smell when putting the engine under heavier loads (e.g. climbing long steady hill on highway) in 3rd and 4th gears? wondering if these are related. it's almost a clutch burning smell (under high loads, not the hiccup) but there is no noticeable increase in rpm at a steady speed (50-65mph).
I had the smell!!! It was bad and anytime I got on it or went up hill Iā€™m just thinking ā€œWTFā€. Luckily whatever it was it finally burned off after 20 to 25000 miles later. I have superchips tune and hiccup is still there 3rd gear 2500 rpm
 

T.T.T

Well-Known Member
First Name
Ty
Joined
Apr 23, 2019
Threads
10
Messages
62
Reaction score
13
Location
South Carolina
Vehicle(s)
ā€˜18 Jl 6spd, ā€˜01 Tj Sahara 5spd
thanks both!! it is definitely worse with back windows out, less so with top down, and barely noticeable when fully closed; and always above 35-40mph (usually in the highway speeds). I have brought it to the dealer claiming the clutch smell, because I really didn't think the exhaust would be that bad (smells more like oil than gas burning), and it takes about 5-10 seconds after the heavy load to hit and then only lasts a few seconds.

not happy that it happens, but happy to hear that others have noticed it as well and is likely (hopefully) just the exhaust in the higher rpm range under load.

thanks!!
Itā€™ll burn off eventually mine was bad
 

T.T.T

Well-Known Member
First Name
Ty
Joined
Apr 23, 2019
Threads
10
Messages
62
Reaction score
13
Location
South Carolina
Vehicle(s)
ā€˜18 Jl 6spd, ā€˜01 Tj Sahara 5spd
Did anyone get there 3rd gear ā€œhiccupā€ resolved???
 

Sponsored

BeeLDub

Well-Known Member
First Name
Brandon
Joined
Oct 16, 2017
Threads
4
Messages
279
Reaction score
380
Location
Eastern PA
Vehicle(s)
2021 Wrangler Willys, 2019 Cherokee Limited
Occupation
Structural Engineer
Did anyone get there 3rd gear ā€œhiccupā€ resolved???
I can't actually tell you the last time I felt it... But it's never been in for anything more than 1 of my free oil change/tire rotations - and they typically make sure the ECU has any/all updates.
 

T.T.T

Well-Known Member
First Name
Ty
Joined
Apr 23, 2019
Threads
10
Messages
62
Reaction score
13
Location
South Carolina
Vehicle(s)
ā€˜18 Jl 6spd, ā€˜01 Tj Sahara 5spd
I can't actually tell you the last time I felt it... But it's never been in for anything more than 1 of my free oil change/tire rotations - and they typically make sure the ECU has any/all updates.
I appreciate the response. Given that i put an exhaust on it, itā€™s very noticeable. On top of using the flashpaq tune from superchips, and a pedal commander it did make it a lot more fun to drive, but i just traded my Jeep in to the dealership after four years. So I have an unlocked flashpaq and a pedal commander if anyone wants to buy it.
 

TheDukeofLark

Well-Known Member
First Name
Zach
Joined
Apr 19, 2021
Threads
3
Messages
90
Reaction score
139
Location
SW MO
Vehicle(s)
21 JLUR M/T
I can't actually tell you the last time I felt it... But it's never been in for anything more than 1 of my free oil change/tire rotations - and they typically make sure the ECU has any/all updates.
I was the same, thinking it had gone away, until the last few days. I am now feeling it again and wondering if it has anything to do with temperature, or maybe even summer/winter gas formulations. I drive the same roads pretty much every day, and at about the same speeds. To go three months without feeling it, then suddenly it warms up and the "clunk" comes back multiple times, I'm suspicious...

I spoke to my dealer about this last fall, and they looked it over for two days, then had a tech ride with me. I was able to reproduce it with the tech in the car. He acknowledged that it was there, but they looked it over again and couldn't figure out what it was. Their theory was something turning on, like maybe the a/c compressor. I've had everything off the last few days, so unless the A/C compressor is being used for another system/process, I think that is ruled out.

The service manager actually listened and seemed to take it seriously (I know many here have dealer horror stories.) He said the biggest hurdle to opening a case with Jeep was that they would have to drive another jeep in the same configuration with similar miles, but finding a 6spd would be hard.
 

T.T.T

Well-Known Member
First Name
Ty
Joined
Apr 23, 2019
Threads
10
Messages
62
Reaction score
13
Location
South Carolina
Vehicle(s)
ā€˜18 Jl 6spd, ā€˜01 Tj Sahara 5spd
I was the same, thinking it had gone away, until the last few days. I am now feeling it again and wondering if it has anything to do with temperature, or maybe even summer/winter gas formulations. I drive the same roads pretty much every day, and at about the same speeds. To go three months without feeling it, then suddenly it warms up and the "clunk" comes back multiple times, I'm suspicious...

I spoke to my dealer about this last fall, and they looked it over for two days, then had a tech ride with me. I was able to reproduce it with the tech in the car. He acknowledged that it was there, but they looked it over again and couldn't figure out what it was. Their theory was something turning on, like maybe the a/c compressor. I've had everything off the last few days, so unless the A/C compressor is being used for another system/process, I think that is ruled out.

The service manager actually listened and seemed to take it seriously (I know many here have dealer horror stories.) He said the biggest hurdle to opening a case with Jeep was that they would have to drive another jeep in the same configuration with similar miles, but finding a 6spd would be hard.
From my experience with the hiccup it wasnā€™t a metal clunk but an actual hiccup that you could hear in the rpm and feel a slight jolt. I knew exactly what speeds and rpm it would do. Having an exhaust really exacerbated it. I wondered if it had something to do with the the throttle tuning being indecisive if staying in economy mode or going into overdrive. Idkā€¦ I can tell you that a superchips tune did nothing to fix the hiccup. Made the jeep drive better but did nothing for the hiccup.
 

TheDukeofLark

Well-Known Member
First Name
Zach
Joined
Apr 19, 2021
Threads
3
Messages
90
Reaction score
139
Location
SW MO
Vehicle(s)
21 JLUR M/T
From my experience with the hiccup it wasnā€™t a metal clunk but an actual hiccup that you could hear in the rpm and feel a slight jolt. I knew exactly what speeds and rpm it would do. Having an exhaust really exacerbated it. I wondered if it had something to do with the the throttle tuning being indecisive if staying in economy mode or going into overdrive. Idkā€¦ I can tell you that a superchips tune did nothing to fix the hiccup. Made the jeep drive better but did nothing for the hiccup.
Yeah, I would agree with you. I should have used the "hiccup" verbiage that others have used.
Sponsored

 
 



Top