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Hesitation, Stutter and Jerk when accelerating at certain speeds?

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181K views 28 replies 21 participants last post by  carapatsch  
#1 ·
I've had this issue since I got the truck but it seems to be getting worse. Basically, anytime I have to accelerate full throttle like entering a highway and needing to merge, or changing lanes on the highway...etc...this issue occurs nearly all the time.

When I have to floor it, there is a second or so of hesitation and lag, followed by what I could really refer to as "turbulence". It's a combination of a stutter and jerk until the truck kicks into gear and accelerates. This is a significant issue because entering a merge lane on a highway can be dangerous which is why I floor it to give myself time to get in lane and not have a person have to slam on their brakes because i'm not getting up to speed.

I spent about 10 minutes on a less congested highway the other day and just got to certain speeds and floored it and I noticed this issue seems more significant accelerating from 40, 50 or 60mph, vs. 20, or 30mph.
So if I floor it from 40, 50 or 60, the issue I mentioned occurs nearly all the time. From lower speeds if I floor it, the issue isn't present.

Any idea what could be the cause here? Thanks in advance. :smileup:
 
#2 ·
I've posted numerous times on this very same condition - always from part throttle, cruising, to downshifting when entering a highway or something. It'll shudder, like it can't quite fully downshift, and I have to let off completely and then push the pedal again to stop it from doing that. It's troublesome. I've tried to duplicate with my dealer, but I can't duplicate it reliably. Always seems that if I'm in MDS at the time, this happens.
 
#3 ·
@Turbo,

I could definitely duplicate this issue with my dealer as long as they had 10 mins. to hop in the passenger side of my truck and go for a drive to the nearest on ramp of the closest freeway.

Could this issue have something to do with the electronic throttle control? Isn't there an electronic throttle control module or something I read about? Anyone have any ideas? :Hey:
 
#6 ·
I have the exact same issue on my 09. I have the MDS activated at the moment,just coz its winter and im just cruising around. Last night i disabled it and gave her a run for about an hour and had no hesitation or stutter. Even on particular ramps where i know it was happening. I dont know if this is the case for everyone but it worked for me.....It's worth a shot.
 
#7 ·
I have the exact same issue on my 09. I have the MDS activated at the moment,just coz its winter and im just cruising around. Last night i disabled it and gave her a run for about an hour and had no hesitation or stutter. Even on particular ramps where i know it was happening. I dont know if this is the case for everyone but it worked for me.....It's worth a shot.
I have a Predator so I can deactivate MDS with the click of a button. I'll go for a run this weekend and duplicate the problem a few times, then disable MDS and go for another run and see if that makes any difference. I'll reply back after I've found out. :smileup:
 
#9 ·
Alright, I disabled MDS with my Predator, and I just ran some runs on the highway and it appears Col is correct, I too disabled MDS and there was absolutely no hesitation or stutter at all! She drove smoother then she ever has! So MDS is definitely the culprit here. I know it sucks that those who don't have a predator or way of disabling MDS have to live with this..but at least we know what the actual "cause" is now.

I'll drive this tank of gas with MDS disabled and see how much worse it is then normal. As long as it is livable then I'll probably keep MDS off most of the time. If the MPG drop is significant then i'll enable MDS but anytime I'm entering a highway/merge lane, or have a need to floor it i'll try to do a quick stop and go FIRST to get OUT of MDS then floor it.

So it looks like your assessment of being in MDS and MDS maybe being the culprit was correct turbovsix. Thanks for the info COL.....that was an easy fix! :smileup:
 
#28 ·
Alright, I disabled MDS with my Predator, and I just ran some runs on the highway and it appears Col is correct, I too disabled MDS and there was absolutely no hesitation or stutter at all! She drove smoother then she ever has! So MDS is definitely the culprit here. I know it sucks that those who don't have a predator or way of disabling MDS have to live with this..but at least we know what the actual "cause" is now. I'll drive this tank of gas with MDS disabled and see how much worse it is then normal. As long as it is livable then I'll probably keep MDS off most of the time. If the MPG drop is significant then i'll enable MDS but anytime I'm entering a highway/merge lane, or have a need to floor it i'll try to do a quick stop and go FIRST to get OUT of MDS then floor it. So it looks like your assessment of being in MDS and MDS maybe being the culprit was correct turbovsix. Thanks for the info COL.....that was an easy fix! :smileup:
If you have a gear selector on the shifter you can deactivate the mds by placing in 6th gear and it deactivates mds but will truly deactivate mds by doing said procedure and also holding down tcs button until the dash light for tcs goes out
 
#11 ·
Well I see I'm late to the party but yes it's the good old MDS. In the city I usually drive it in 5th so the MDS doesn't kick in. Nothing worse than being in city traffic when you do have to honk on it and that damn studder and hesitation cost's you a break in traffic. I'm now in the habit of dropping to 5th whenever I merge, that way the Hemi performs the second I tell it to!
 
#13 ·
I'm kinda thinking that many who improved their intown mileage by disabling the MDS did so because they may have been mashing around on the gas pedal in response to their dislike and annoyance with the operation of the MDS. If you constantly listen to the MDS in town, and you operate the gas pedal in a manner to try to prevent the feedback and sound of the MDS, I think you'll get lower mpg. If you drive the truck and disregard the MDS, I think you get better mileage. Can MDS be noticeable at times, especially in intown driving?...yes. If you're one of those who is really bothered by the feedback, should you disable the MDS in town?...yes. Still, I think the truck gets better mileage in town if you can drive normally without any regard to the MDS. I think Chrysler/Dodge actually knew what they were doing for mileage improvement with MDS. They may also have known what they were doing with an easy ability to disable MDS with the gear selector for those who are bothered by it...without having to buy a tuner.

I don't know...I think some of us who have owned fire-breathing hot rods in the past with lumpy cams and other "rough spots" tend to ignore the MDS better than others, but I understand how people are different and can sometimes have an issue with it.
 
#15 ·
Not really sure what you're asking.



Wikipedia said:
Chrysler's Multi-Displacement System (MDS) is an automobile engine variable displacement technology. It debuted in 2004 on the 5.7 L modern Hemi V8. Like Mercedes-Benz's Active Cylinder Control, General Motors' Active Fuel Management, and Honda's Variable Cylinder Management, it deactivates four of the V8's cylinders when the throttle is closed or at steady speeds.
The system was first offered only on passenger cars, since the heavy demands of trucks would interfere with its operation. However, it was recalibrated for 2006 and will be offered on all seven models, including SUV's and 1500 series trucks, using the 5.7 L engine.
Chrysler expects that the technology will boost economy by 10% to 20%. In the Jeep Grand Cherokee with MDS, highway fuel mileage for the V8 is the same as the V6 at 21 mpg (11.2 liters per 100 km).
In order to preserve the characteristic rumble of the V8 engines, Chrysler and Eberspaecher North America designed a special exhaust system for MDS-equipped vehicles. This includes four separate mufflers, two large central ones for V8 mode and two smaller ones near the tailpipes for four-cylinder mode. Unlike the system used on Mercedes-Benz V12 engines, also designed by Eberspaecher, the system is mechanically passive.
You bumped this so I don't have to.


Thanks to everyone who discussed this problem.

I have a 2012 Ram 2500 that does not drop to 4 cylinders (Thank f'n god) & it's smooth as hell when accellerating.

All that said, my 2013 Challenger RT (v8, so nearly the same engine) is a dog, jerks & drives like ****. I had a valve body replaced to fix the horrific jerking. It doesn't jerk as badly, but it's a major problem.

This thread confirmed my fears & critical attitude towards MDS. MDS causes me a LOT of issues & I have drive like a grandma at times with passengers who have back & neck problems. I'll be looking into a programmer to disable mds & engine breaking.


I like my Ram & the Challenger, but the power train leaves a lot to be desired. :smiledown:
 
#18 ·
Disabling the MDS

Wouldn't clicking the transmission down button once (to 8 or whatever gear you are in at the moment) effectively disable MDS until you up-click all the way out of the top gear override? So those of us w/o a Predator would have essentially the same ability to shut down MDS?
 
#20 ·
issues with MDS or some thing else?

So for about 6-8 months I've been noticing when I'm cruising @ 30-40MPH and the RPM is @ or around 1100-1300 and I have to floor it there is a slight hesitation before the truck actually starts to accelerate and I can hear/feel things shaking from the tranny/drive shaft for a second as well.

I was searching online and found this topic in our very own forum. ha!
I'll have to check my BullyDogGT Tuner to see if my MDS is off, according to these symptoms it's not.
 
#21 ·
Remove your tuner, disconnect the battery for 30-60 seconds, drive ~30 miles normal and then see, if it's still there. if so, check the freeze frame and see the activation for the MDS. I'm pretty sure there is the issue. can be also the cam sensor. they get dirty sometimes.
yeah- I'm not a friend of programmers. 90% you mess the setting up. most of the people using it, have no idea, what they actually doing, even though they think they do. Or can you write a PCM Programming on your own? if you don't - I can tell you- you have no idea what, where and how you messing around.
but that's just my personal opinion.
 
#22 ·
I've had this issue since I got the truck but it seems to be getting worse. Basically, anytime I have to accelerate full throttle like entering a highway and needing to merge, or changing lanes on the highway...etc...this issue occurs nearly all the time.

When I have to floor it, there is a second or so of hesitation and lag, followed by what I could really refer to as "turbulence". It's a combination of a stutter and jerk until the truck kicks into gear and accelerates. This is a significant issue because entering a merge lane on a highway can be dangerous which is why I floor it to give myself time to get in lane and not have a person have to slam on their brakes because i'm not getting up to speed.

I spent about 10 minutes on a less congested highway the other day and just got to certain speeds and floored it and I noticed this issue seems more significant accelerating from 40, 50 or 60mph, vs. 20, or 30mph.
So if I floor it from 40, 50 or 60, the issue I mentioned occurs nearly all the time. From lower speeds if I floor it, the issue isn't present.

Any idea what could be the cause here? Thanks in advance. :smileup:
I have the same exact issue
 
#24 ·
for my truck it ended up being a few things. Cam shaft, lifters, and I can't remember what else. I ended up getting rid of it. I was so upset about it but I couldn't afford to fix it and I don't know anything about engine internals. Good luck.
 
#26 ·
Oh man. This is my issue too, but didn't start till I reached 100k miles.
First thing I noticed was a code that said coil#1 was bad. And I figured it was time for spark plugs per the manual and I was ok with that. I have not done the plugs yet. Then the code went away on its own. A few days later a different light came up. It's an outline of the engine and it was flashing for a bit and now comes on temporarily when I get the shudder under hard accel. It feels like transmission but I'm not sure. It's a 2014 2500 with 6.4 hemi and MDS. I bought it new back in 2014 and has been pretty good so far. I guess I'll replace the plugs and that coil. Heard the plugs are a PITA to get to the back ones near the firewall. Has anyone here corrected this issue with plugs and coils?
 
#29 ·
I have a 2012 Dodge Avenger SXT, and I’ve always noticed the exact same issues everyone on here is talking about. My dad drove it this past weekend and asked me about it and I was just like, “I don’t know it’s always done that.” I’m not sure if MDS would affect my car since I don’t have an 8 cylinder engine, not even a 6, my car is a 4 cylinder engine.