[quirkySquirt]

Maybe I'm overreacting but when parked with EPB engaged and without any battery range left, my Volt rumbles/vibrates quite a bit when the ICE comes on for a bit to charge the battery. Every time the ICE comes on, the gauge that represents the ICE RPM revs to about 1/4 of the max RPM range then settles to 1/5 of the max RPM range. During the initial rev, it feels as if my Volt wants to lurch forward if it weren't for the EPB. Anyone experience this? Does the Volt to you appear to want to lurch forward?

Didn't notice this before as I rarely sit in the Volt parked with it on and consuming ICE power. It's starting to get colder so I have ECO HVAC on, 50% fan, consuming 3 kW according to the Classic Enhanced DIC.

 

[llninja]

Sounds normal to me. The ICE runs at its own speed. Sometimes I'll be stopped and the ice is running at higher rpm and then while driving 40 mph, sometimes it will shut off. Just remember the ICE drives the generator which drives the electric motor which drives the wheels. The ICE usually doesn't drive the wheels (though it will help, sometimes, in particular instances, for fuel efficiency)

Another phenomenon is that after driving in smooth EV mode, any ICE feels bad. But just jump into a used dealership loaner car and feel the vibration of a well used Chrysler 200, that will bring back the memories of what a real vibrating ICE feels like. If you volt feels worse, then bring it in as it's not supposed to have that much noise, vibration, and harshness.

 

[BAZINGA]

Compared to the silky smooth and silent operation of the battery powered operation of the Volt, ICE operation can be jarring to some.

I found THREE things that helped my Gen I's, the more hours on the ICE the smoother it got and I changed the Dino oil to Mobil 1 full synthetic oil and adding a bottle of fuel injection cleaner to the tank just before a long trip.

But the more hours/miles on the ICE and it will smooth out.

 

[audguy]

Judging from the Classic Enhanced DIC you have a Gen 2 volt. I have the same problem, just got it back from being "fixed" today, still has the same problem. They replaced number 4 spark plug due to excessive fouling and misfire all according to document 4424724.

 

[JeremyK]

There may be some emissions algorithms in place that operate the ICE a little differently when first starting, in order to get fast light-off of the catalyst. My wife's Mazda actually does some tricks with timing/spark/fuel that result in a very noticeable noise and vibration for the first 15-30 seconds or so of running.

Gen I Volt seems to NOT do this. When my ICE starts, it is usually imperceptible for a short period of time, and after that warm up period it is then allowed to rev and be loaded by the generator (and things get noisier). Gen II Volt may have different programing for initial engine start. Maybe somebody can comment that has experienced both Gen I and Gen II.

 

[audguy]

I've had both a '13 and a '17 the '17 is much rougher on startup.

 

[DonC]

On my 2011 MY this would be normal. How rough the engine runs is highly dependent on the situation. Most times it's pretty gentle, but sometimes it runs hard and is quite rough. More noticeable at lower speeds.

 

[Steverino]

I think some of this is caused by hearing and feeling an engine high revving while stopped at a light or while the car is moving slowly. Hearing the engine rev like it goes against experience. You expect the car to be roaring down the road rather than stopped at a light. Your brain is used to the engine barely running at those speeds. At highway speeds you would not have this cognitive dissonance.

People forget that the ICE is mainly an electric generator pumping electrons into the battery, mostly disconnected from the speed of the car. So it's revving away totally unconcerned as to what's going on with the gas pedal. Again, this is contrary to people's experience with gas cars.

 

[jbakerjonathan]

I'm guessing... the lurch is a reaction torque due to the generator engaging.

 

[quirkySquirt]

Hmmm, good explanations. I may mention it since I also have that backfire problem when accelerating from a full stop with no battery range. Thanks, everyone!