car was in the shop for 2 weeks, 400 miles driven by 2 employees there and could feel what I feel while cruising. GM says everything is as it should be so I guess I have the most expensive 4 cylinder car ever built that I am stuck with. I did put the selector to sport mode instead of touring and will have to paddle shift to get up over hills. Really disappointed with their R&D.

 

I wonder if the problem is exclusive to your car. If another car behaves the same it is a bad design and nothing much you can do about that. If you drive another car and it behaves differently you have a legitimate case for complaint and you should demand it be fixed. You spent enough money and should not be disappointed.

 

A large percentage of the time mine shifts back to V8 quickly when load is applied. But sometimes hangs in V4 with loss of throttle response, garbled exhaust sound then vibration and finally back to V8 and all is well. I too am disappointed that corrective action by GM has been absent on this issue. I know it can be tuned out, but am not confident enough to void powertrain warranty on this new LT1 yet! This is a problem GM should correct with out turning buyers sour towards them. Is a smooth running V8 a thing of the past. Hot Rod Mag Dec Issue talks about boost in V4 mode on Z06, interesting they would allow such programming.

 

And so is your warranty...

 

Indeed. Come on GM, can't you reprogram it so AFM is disabled in track or sport mode? V4 in Track mode, what are they thinking???

 

Excuse me, but the OP has a 2014 A6, not a 2015 A8.

 

I notice this all the time in my 2014 A6 as well. Seems if you are cruising and then all of a sudden hit the accelerator to get moving or pass somebody, it has a hesitation to it before it kicks in. kind of makes you lurch forward for a quick second before you get moving. I hate it but figured it is what it is. I would never tune it myself to get around this, but believe that Sport Mode and Track should be V8 and nothing else. Touring and below should be V4/V8 capable, not Sport or Track. Makes no sense. Do you think GM will do anything about this?

 

I have a similar problem but I do not think it is the transmission. On full throttle acceleration from a 40 MPH roll the car would hesitate in touring mode. I decided to try sport mode and for a while it was fine.

The problem came back, it would hesitate and now backfire before it accelerated regardless of being in sport mode. Brought it to the dealer and they could not duplicate the problem

Since then I have noticed that I can not change the sound management (NPP) off. On several occassions I have also noticed that if I accelerate hard in sport mode but slow down before the anticipated next gear I can not choose the driving mode. It will go from track to weather and I can not pick anything in between. Once I stop and turn the car off the driving modes are fine.

I am really frustrated as these things happen ocassionally (with the exception of changing the sound management). For now the car sits in the garage until I have some time to actually record what is going on as the answer "could not duplicate the problem" is no answer and just a waste of my time.

I called GM customer service and they stated that no one has reported a similar problem and yet there is this thread. Looks like the old GM

 

Mine does the same, but not as bad as described in the OP's post.

When just at a steady drive and I give it a little more gas, I can feel it more in the pedal than anything else. Just a slight shutter like it's switching back to V8 and trying to go down to 5th gear or something. I just don't get the "slowing" down feel like he stated.

I agree V4 should not be working in Sport or Track mode. I bought a sports car and I like to drive it as one. Long trips sure the V4 mode is good and it's great for future engine advancement.

 

This sounds to me like a serious oversight by GM engineering. Its a performance car isn't it ? Why would they not at least give auto (A6 / A8) owners the option to use Eco mode.

I have an M7 so Eco Mode only if I choose to select it. On a recent trip I gauged the difference in fuel economy between Touring and Eco Mode and found that the difference was somewhere between 1 and 2 miles per gallon. What was very evident is the feel of the car in Eco Mode, engine does not sound right, shakes / vibrates, just sounds un healthy and I cant imagine what it will do to the engine long term. For me I will never put the car in Eco Mode again. I didn't buy it to save $5.00 on a tank of gas, if I wanted that I would have bought a cruze.

The M7 is a great transmission with the LTI, now if GM would just get rid of the stupid 1st to 4th gear mandatory shift. Who makes these decisions on sports car ?

 

 

I have the same issue with my 2014 A6 when in drive. I can definitely feel the V8 activation when I accelerate...but I also feel a lugging/shuddering as well. When using the paddles, all is ok. I have just assumed it is in the programming of the transmission, and been patiently waiting for an update.

 

Too many of us A6 owners are patiently waiting!

 

My A6 transitions from 4 to 8 and 8 to 4 seamlessly. I've looked down at the gauges and watched the V8/V4 light several times during the transition.

If your car is lurching or lugging/shuddering or you have a short loss of power then something is wrong with your system.

 

I am hoping the Chevy Customer Service folks can jump in here and let us know their thoughts on this? Is it normal for it to kind of delay when you hit the gas from V4 to V8 or is it an issue that needs to be looked at. If i am driving and it is in V4 and i just casually open it up (very easy), you don't notice the lunge. You only notice it when you put the peddle to the metal and it kind of lunges. Really would like to know what is going on here.

 

My experience as well..

 

They won't. Customer service positions are low wage entry level positions. They aren't techs, and could get in big trouble expressing any opinions at all... (in case you haven't noticed this already)

 

That's a tough situation to have to accept. BTDT too.

 

Same here.

 

.....these people are nuts .my words almost to the t. before the 8 speed came out . they can't even get it right for a 6 speed , well'' lets add 2 more gears nothing like doing 70 in 8th on
4 c. and trying to give it gas , it will drink more gas trying to pick up speed than you will ever save with the 4. in 8th.