Rev/Shifting issues

[Matt_KW]

This is an issue I brought up to two Chevy dealerships, Healey Chevy and Romeo Chevy. I have the 2012 Chevy Sonic LT Automatic. When the car shifts you can feel it more then others. Sometimes you don't feel it at all but other times it feels as if I slammed on the brakes. It seems like the rpm's drop a lot more when its a harder shift. The dealership said this was normal, in my opinion it would only be normal if its consistent. Being that it varies day to day....its not normal. Have any of you had this issue? Would this be an issue with Spark Plug gapping, my gaps are all different atm. Could the Trifecta Tune fix this issue. Thank you for any information you can provide.

I am bringing my car back to Romeo Chevy in Kingston, NY to have them look over about ten problems I am having including that one.

So far every single time I brought it with this concern they told me "We could not duplicate the sound or action". Might as well get it on video next time around.

Thank You Again!

 

[Sneakerfix]

Has nothing to do with gap.. I would say it's the transmission wave plates but it doesn't happen all the time is your sonIC a 2012? Have you tried to reset the battery?

 

[Paradox]

I hate to say it, but the automatic transmission is subpar for sure. I've been having issues with my transmission, from day one, I've been to multiple dealers, and for now I'm guessing there isn't a fix. Unless you have a VERY proactive dealer and will take your transmission out and inspect it. If you look into the car complaints for 2012-2013 years, there are numerous accounts of rough shifting and slipping on the automatics. Personally my transmission shifts HARD, in stop and go traffic especially, I've had people think we've been rear ended it slams so hard in the next gear. As for varying, so does mine, my transmission slips from 2-3 gear change when it's cold out, anything over 12 C and it doesn't do it. If I cruise down a hill letting it coast(no throttle), transmission has no idea that the car has sped up, and can freely rev up to as high as 4200 rpm (usually 3500 rpm) on my car before it engages the gear. Also, when braking hard and then turning a corner it's still in 5th gear, so car jitters badly because engine is at 800 rpm...
I got the Full Trifecta tune and it hasn't changed a thing, what I found helps the most is to reset the TCM if you do have the Trifecta tune.

If you can live with the transmission, I think it's an awesome car, I personally love mine. Wouldn't trade it for any other car in its class, and honestly looking around at other cars in its class, problems are far worse on other makes. The only thing I regret is buying a first year production car,because there will be problems. I haven't heard any issues with the 2014 auto transmission yet, but I could be wrong. If you find anything let me know...

 

[Matt_KW]

Yeah I have the 2012 sonic "Sneakerfix". My car had the turbine shaft recall around 20k miles which I had replaced. This issue has happened before and after the turbine shaft replacement. The dealership I recently went to said the tranny sounded like it was slipping, I am going to bring in back in this upcoming week to have them diagnose it further. Being that this is a common issue with the automatic transmission you would think they would recall it and do a massive overhaul....but then again to them that would be a waste of money. I love the car, just have been experiencing some major issues with it.

The worst issue so far is they forgot to solder the power wire to the fuse box(from what the tech told me)....I hit a bump and the wire popped off and I lost complete power to my car..thank God I was in a parking lot.

 

[Sneakerfix]

Yeah I have the 2012 sonic "Sneakerfix". My car had the turbine shaft recall around 20k miles which I had replaced. This issue has happened before and after the turbine shaft replacement. The dealership I recently went to said the tranny sounded like it was slipping, I am going to bring in back in this upcoming week to have them diagnose it further. Being that this is a common issue with the automatic transmission you would think they would recall it and do a massive overhaul....but then again to them that would be a waste of money. I love the car, just have been experiencing some major issues with it.

The worst issue so far is they forgot to solder the power wire to the fuse box(from what the tech told me)....I hit a bump and the wire popped off and I lost complete power to my car..thank God I was in a parking lot.

2011 to early 2012 6t40 transmissions have weak wave plates tell your dealer about the wave plants being updated. I haven't had one issue since my rebuild also make sure they updated you're TCM program and replaced the TCM with a new one and not just cleaned out the old one or you will be back at the dealer within a week

 

[ChrisJ]

2011 to early 2012 6t40 transmissions have weak wave plates tell your dealer about the wave plants being updated. I haven't had one issue since my rebuild also make sure they updated you're TCM program and replaced the TCM with a new one and not just cleaned out the old one or you will be back at the dealer within a week

But 1.8 Sonics have a 6T30?