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Discussion Starter #1 (Edited)
My 2017 built 06/16, delivered on 08/20 and have driven almost 3400 miles, my ICE currently has 19 miles on it, 4 prior to delivery and 4 back in Sept when my daughter was driving. So yesterday if was 4 degrees when I departed from work, knowing ERDTT would cycle during my 11 mile commute to work I opted switch the car to HOLD mode to avoid the cycling and subsequent poor fuel mileage associated with short trips. But almost immediately I noticed a constant "SURGING".

Granted I only have driven my 2017 Volt about 10 miles on the ICE out of almost 3400 miles so maybe I'm being a bit premature, but neither of my Gen I' behaved this way when new.

Suggestion/comments?
 

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Could also be clutch break-in, but make sure you're up to date on all your recalls, etc.

If you don't mind sparing a few bucks for gas, you could drive a tank entirely in Hold mode (somewhat simulating FMM...) to break in the clutch.
 

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Have had my 2017 LT for about 2 weeks now, and am noticing this "chuggle" problem too. Seems to only be when the gas engine is running, in CS/HOLD mode or ERDTT mode.

It feels like a constant surging.
 

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Discussion Starter #6 (Edited)
My 2017 was just in for the most recent recall and supposedly I’m up to date at least on "recalls"


Not sure about TSB's though.

I don't want to burn gas if this is a software issue, so I'll book another appointment with my dealer. More to follow.
 

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Could also be clutch break-in, but make sure you're up to date on all your recalls, etc.

If you don't mind sparing a few bucks for gas, you could drive a tank entirely in Hold mode (somewhat simulating FMM...) to break in the clutch.
Hope that works for the OP but it didn't for me. I've put ~450km in Hold now across two trips and the chuggle is still bad during ERDTT.

In Hold mode I don't notice any chuggle, but with the ACC on there is a lot energy wasted with on/off power application with no one in front.

EDIT: Forgot to add my 2017 Volt was built on 08/16. The app has no recall and the linked threads imply only the 06/16 or older have a recall/TBS.

Yet I still have a bad ERDTT chuggle. I'm thinking there are issues remaining with controlling the load on the ICE during ERDTT.
 

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I have a similar issue and so I am mentioning it in this thread rather than starting a new thread. On these cold mornings my 2016LT starts in ERDTT mode and I drive for a few minutes in that mode. I am used to the engine racing and slowing in an unpredictable fashion while in ICE mode, having nothing to do with whether I step on the accelerator or not. What disturbs me is that pushing the REGEN paddle revs the engine and does not slow down the car. It is only when it shifts into EV mode that the REGEN works normally. Does this sound normal? FYI, I have had the 32340 recall (in August) and I had the Reduced propulsion recall 16055 a few days ago. Any ideas would be greatly appreciated.
 

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Sounds like the battery, being cold, is programmed not to charge from ICE or take regen. This would also effect the loading on the ICE. Sounds like a corner test GM may not have tested
 

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My 2017 built 06/16, delivered on 08/20 and have driven almost 3400 miles, my ICE currently has 19 miles on it, 4 prior to delivery and 4 back in Sept when my daughter was driving. So yesterday if was 4 degrees when I departed from work, knowing ERDTT would cycle during my 11 mile commute to work I opted switch the car to HOLD mode to avoid the cycling and subsequent poor fuel mileage associated with short trips. But almost immediately I noticed a constant "SURGING".

Granted I only have driven my 2017 Volt about 10 miles on the ICE out of almost 3400 miles so maybe I'm being a bit premature, but neither of my Gen I' behaved this way when new.

Suggestion/comments?
I'm not sure "surging" is the "chuggle". What do others think?
 

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I'm not sure "surging" is the "chuggle". What do others think?
I've got the same feeling. I don't really know what "chuggle" means but to me it actually seems like drag being applied. Think of when you hold the regen paddle and then let go and then hold it again. But in a tighter sequence and with a bit less force. It feels like surging because I think the sudden "smoothness" between drag events makes it feel like surging forward since your foot is on the gas and you're moving forward and your brain is in that mindset. It seriously feels like a clutch engaging and linking the engine and you're getting engine braking (or as much as this kinda mechanical setup replicates) and then it disengages and you have far less drag and it feels completely disconnected and pure electric propulsion. It makes sense it would work this way except for the frequency of the cycle. This is a on/off like every half a second to one second. No way can that be to maximize fuel saving.
 

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I have a similar issue and so I am mentioning it in this thread rather than starting a new thread. On these cold mornings my 2016LT starts in ERDTT mode and I drive for a few minutes in that mode. I am used to the engine racing and slowing in an unpredictable fashion while in ICE mode, having nothing to do with whether I step on the accelerator or not. What disturbs me is that pushing the REGEN paddle revs the engine and does not slow down the car. It is only when it shifts into EV mode that the REGEN works normally. Does this sound normal? FYI, I have had the 32340 recall (in August) and I had the Reduced propulsion recall 16055 a few days ago. Any ideas would be greatly appreciated.
If the engine is revved up a lot, the regen paddle will not do very much. The reason the engine revs up even more when you press it is because pressing the regen paddle usually forces the clutch to completely disengage the engine from the drivetrain, so its load decreases, but it is still putting power into the battery. The regen paddle is thus less effective because the battery can only accept so much charge, and the engine is providing a lot of that already.
 

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I decided to run my car on Hold mode a few days ago with a fully charged battery. When I used the regen paddle it reved the engine instead of the normal regen braking. I think this happens because the batteries were full and there was no place for the regen power to go. So instead the car uses engine braking which causes it to rev? I am going to try this again soon with a depleted battery to see if it acts differently. My fuel economy was also not very good (33.6MPG). Perhaps that was because I could not take advantage on the normal regen ability of the car when braking, or maybe it was just because it was a cold day.
 

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After reading this thread it appears that there are at least two and maybe three different drivability issues. Some of them I think would occur with all Gen2 cars, but not all of them.

I have not observed any of these issues but given the descriptions the original "chuggle" issue occurs when driving in charge sustain and at a steady highway speed greater than 45 MPH. I have assumed the speed. It would be interesting to know at what speed ranges it occurs, how long does it take to begin and if it ever stops during the drive.

It seems there is some threshold that is being crossed that causes a change which pushes it below the threshold and then it changes again only to cross the threshold again and so forth. It needs threshold hysteresis.
 

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Discussion Starter #15 (Edited)
I've decided to run the ICE some and see if that's all is needed - breaking in. Hate to burn gas since my daily driving needs seldom exhaust the battery and with a level II EVSE can easily top off the battery between trips. SO LONG 99.7% electric miles.

So I drove it an additional 22 ICE miles this am. I did notice the stutter or CHUGGLE or whatever occurs between 35 and 55 MPH at higher speeds it was non-existent. I did notice the stutter seemed to lesson the more miles I drove. I'm going to do all my DD in HOLD for the next few days and see if that doesn't fix the problem. My DD commute is 22 miles. It'll only cost me a couple of gallons of dealer gas. Right now I have 48 miles on my ICE.

I'll post daily updates.
 

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Get ready to burn lots of gas my 2017 had chuggle for about 3000 gas miles. Its pretty much gone now. But I do feel it a little bit from time to time on erdtt.
 

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I'm not sure "surging" is the "chuggle". What do others think?
Surging is the most accurate way to describe chuggle.
I definitely still notice it on mine after about 10 months of driving, although it has improved. My car runs terrible when the gas engine kick on cold… I’ll be starting a new thread regarding this shortly.
 

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Surging is the most accurate way to describe chuggle.
I definitely still notice it on mine after about 10 months of driving, although it has improved. My car runs terrible when the gas engine kick on cold… I’ll be starting a new thread regarding this shortly.
How long does it surge? I bought a 2017, which seems to drive fine; we did about 95miles of highway driving, during a day trip in mild temperatures and the ICE transition was seamless.

I also test drove a 2017, that turned out someone else was already buying. It didn't have any battery charge, and I remember I noticed the ICE was a little rough at one point at maybe 40mph, going a bit louder than expected? I guess it didn't concern me much. And the 2017 I wound up buying had a fully charged up battery.
 

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I have three Gen2 Volts in my household and all three have shown the chuggle either when in HOLD or after draining the battery. It definitely appears to lessen with mileage as my Volt has 8,000 miles and only occasionally do I feel the chuggle. Both of the other two Volts have about 4,000 miles and experience it more often still.

Here is an interesting observation though... today during ERDTT mode, I experienced mild chuggle symptoms. I switched the view to FLOW mode and noticed that it appears that the chuggle was happening when the engine is providing charge to drive at the same time that it is giving excess charge to the battery. Never noticed this before and wondering if anyone else has...

Next observation was upon getting off the highway onto the exit ramp, still in ERDTT mode, I coasted most of the way on the exit ramp and was feeling the chuggle even though I was not pressing the accelerator pedal. First time noticing that as well.

Any thoughts on these two observations?
 

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...
... I switched the view to FLOW mode and noticed that it appears that the chuggle was happening when the engine is providing charge to drive at the same time that it is giving excess charge to the battery.

This is also what I think it is...Not so sure chuggle isn't something else- nobody has ever recorded it in anyway out side of descriptions posted online. My observation is that it is the one-way clutch for the ICE coming in and out of engagement due to extremely light coast modes where it is on the verge of regen vs propel states. As soon as you give 'er a little gas to accelerate, or maybe for a hill, it chooses a state and doesn't switch back.
Maybe once the friction material of the clutch band burnishes after a few thousand miles, it feels smoother, but what is more likely is that the operator subconsciously learns to avoid the condition that the chuggle occurs in.
 
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