M/T Throttle surge or dip when shifting

[redracer]

Ok, just a couple of observations from driving around my Manual Transmission JLUR...

1 If, at any time while decelerating you press the clutch and go to neutral the engine RPM's will drop to below 700 for a moment and cause a knock sound. Even if you let are decelerating at 3k rpms, it drops all the way below 700rpm then catches itself.

2 If accelerating at a brisk to fast pace and let my foot off the throttle, the engine will give a quick surge of acceleration. This is especially frustrating while trying to shift quickly as if I let off the throttle and clutch at anywhere near the same time, the engine will rev to the red line and stay there until you release the clutch in the next gear. ... and YES, my right foot is resting on the floor while this is happening.

3 The same as #2 can be noted anytime shifting over 4k rpm. letting off the throttle causes the engine to rev higher for a second or two.

Is it just me? This really does not seem like a desired response to taking my foot off the gas.

I've been learning it. dealing with it. and I can predict it. It's just a bit frustrating.

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[The_Phew]

3 The same as #2 can be noted anytime shifting over 4k rpm. letting off the throttle causes the engine to rev higher for a second or two.

Could this be 'rev hang'? It doesn't typically mean higher revs when you let off the throttle (just 'stuck' revs), but it's a very common complaint on modern M/T cars from Honda, Toyota, and others. It's programmed in for emissions reasons, and folks defeat it with aftermarket tunes.

It's possible you have a throttle calibration issue. If you can reproduce it, take it to your dealer. If they say it's normal, ask to drive another 6MT JL. I didn't notice this on my JLUR 6MT test drive, but I didn't rev high either (I knew I wasn't buying that vehicle, and didn't want to thrash someone else's future new Jeep).

 

[TTEChris]

Ok, just a couple of observations from driving around my Manual Transmission JLUR...

1 If, at any time while decelerating you press the clutch and go to neutral the engine RPM's will drop to below 700 for a moment and cause a knock sound. Even if you let are decelerating at 3k rpms, it drops all the way below 700rpm then catches itself.

2 If accelerating at a brisk to fast pace and let my foot off the throttle, the engine will give a quick surge of acceleration. This is especially frustrating while trying to shift quickly as if I let off the throttle and clutch at anywhere near the same time, the engine will rev to the red line and stay there until you release the clutch in the next gear. ... and YES, my right foot is resting on the floor while this is happening.

3 The same as #2 can be noted anytime shifting over 4k rpm. letting off the throttle causes the engine to rev higher for a second or two.

Is it just me? This really does not seem like a desired response to taking my foot off the gas.

I've been learning it. dealing with it. and I can predict it. It's just a bit frustrating.

I haven't noticed those exact issues, but since I've added my exhaust I have noticed that most of the time I depress the clutch & let off the gas the RPMs dip slightly below standard idle RPM and then level back out. I thought it was just my JL, but when I drove my wifes 6spd it does the same thing. It just isn't noticeable unless you look at the tach due to the lack of exhaust noise.

 

[TheWingman]

Ok, just a couple of observations from driving around my Manual Transmission JLUR...

1 If, at any time while decelerating you press the clutch and go to neutral the engine RPM's will drop to below 700 for a moment and cause a knock sound. Even if you let are decelerating at 3k rpms, it drops all the way below 700rpm then catches itself.

2 If accelerating at a brisk to fast pace and let my foot off the throttle, the engine will give a quick surge of acceleration. This is especially frustrating while trying to shift quickly as if I let off the throttle and clutch at anywhere near the same time, the engine will rev to the red line and stay there until you release the clutch in the next gear. ... and YES, my right foot is resting on the floor while this is happening.

3 The same as #2 can be noted anytime shifting over 4k rpm. letting off the throttle causes the engine to rev higher for a second or two.

Is it just me? This really does not seem like a desired response to taking my foot off the gas.

I've been learning it. dealing with it. and I can predict it. It's just a bit frustrating.

Mine does all of these things. I have mitigated #2 and #3 by letting off the throttle before depressing the clutch. It's muscle memory now and I don't even notice I'm doing it anymore. Had a 6spd VW GTI before this, so it took some time getting used to how she wants to be treated. #1 doesn't happen all the time, but when it does I can feel it in the clutch, even if I can't hear it (love the alpine). It's done all this since it was new. Hearing other's jeeps have the same feel makes me more confident that it's normal.

 

[Torero]

Not mine. Unless I am so distracted that I don’t notice any of those things.

 

[Torero]

Not mine. Unless I am so distracted that I don’t notice any of those things.

Ok. I went for a drive and really paid attention. No it doesn’t do anything weird. If I push the clutch in, I have to wait a long time for the RPM to drop to idle. Normal shifting drops about 5-700 rpm before I let the clutch out again in the next gear.

 

[redracer]

Well, It looks like this is normal then. I have learned how to mitigate it for the most part, but occasionally I will still hit the high rev issue, usually when I'm accelerating hard after a short merge or worse turning onto a busy rual freeway with no ramp.

If there was a tune available that took care of this, i'd probably buy it.

As for the dip, I don't mind so much other than it causes a knock that I can hear when driving in town.

Oh well, I still love my Jeep and my MT. I hope that Jeep will improve their tunes with time and we will get the updates.

Thanks guys.

 

[m3reno]

My jeep has those exact issues. I noticed it when decelerating and if I shift up above 2500 rpm. Other than those two issues the manual is super smooth

 

[JeepCares]

My jeep has those exact issues. I noticed it when decelerating and if I shift up above 2500 rpm. Other than those two issues the manual is super smooth

Are you planning on making your dealer aware of what's occurring? Send me a direct message if we can be of any assistance with this process.

Jasmine
Jeep Social Care Specialist

 

[Litfuse]

I have found the throttle calibration on my JL Rubicon 6 speed is the worst I have ever experienced in a drive by wire car. I also think the oem tune is marginal at best. Coupled with the poor gear choices in 4th-6th gears, it really hampers the driving experience.

 

[m3reno]

Are you planning on making your dealer aware of what's occurring? Send me a direct message if we can be of any assistance with this process.

Jasmine
Jeep Social Care Specialist

yes I will be bringing it in soon. busy with work right now but I'll keep you posted

 

[Litfuse]

yes I will be bringing it in soon. busy with work right now but I'll keep you posted

This is not a mechanical issue your dealer can fix. It is in the tune. Until Jeep creates a new tune, this is just a driveability issue. But to be honest, most oem tunes with a drive by wire set up aren’t very good.

 

[TommySM]

Ok, just a couple of observations from driving around my Manual Transmission JLUR...

1 If, at any time while decelerating you press the clutch and go to neutral the engine RPM's will drop to below 700 for a moment and cause a knock sound. Even if you let are decelerating at 3k rpms, it drops all the way below 700rpm then catches itself.

2 If accelerating at a brisk to fast pace and let my foot off the throttle, the engine will give a quick surge of acceleration. This is especially frustrating while trying to shift quickly as if I let off the throttle and clutch at anywhere near the same time, the engine will rev to the red line and stay there until you release the clutch in the next gear. ... and YES, my right foot is resting on the floor while this is happening.

3 The same as #2 can be noted anytime shifting over 4k rpm. letting off the throttle causes the engine to rev higher for a second or two.

Is it just me? This really does not seem like a desired response to taking my foot off the gas.

I've been learning it. dealing with it. and I can predict it. It's just a bit frustrating.

I just test drove the manual JL and google searched this very issue...WOW...very noticeable. I was intentionally going hard through 1st, 2nd and 3rd and revving to almost redline. At each shift the engine acts like the flywheel is soooo heavy it creates an added surge that effects the next shift point...very odd. Also, no place to put my left foot between shifts. Arrrggghhh.

 

[OldGuyNewJeep]

I just test drove the manual JL and google searched this very issue...WOW...very noticeable. I was intentionally going hard through 1st, 2nd and 3rd and revving to almost redline. At each shift the engine acts like the flywheel is soooo heavy it creates an added surge that effects the next shift point...very odd. Also, no place to put my left foot between shifts. Arrrggghhh.

It’s not a sports car, though. I shift mine at 2500 most of the time, and it’s silky smooth. If I need to come up to speed very quickly I’ll maybe rev it out to 4000, but no where near redline. I mean, in 4lo you’re going to rev out a bit, but I think your expectations are off on this one.

 

[m3reno]

yes you have to adjust your driving style a bit but it would be nice to be able to go above 4000 rev's once in a while maybe Not to red line but for a 40,000 dollar vehicle it really shouldn't do this. It did say sport s when I purchased my jeep. my only gripe with the jeep is this, other than that it's an excellent vehicle

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