Transmission Question
Thread Starter
Intermediate
Joined: Nov 2015
Posts: 36
Likes: 0
Transmission Question
I purchased a 2015 Z51 about a year ago and from the time I start it up to about 20 minutes of driving, when I place the car in drive, it hesitates about 5 seconds, then I get a big jerk. I told the dealership about this and they changed the transmission fluid, but it still does the same thing. Has anyone else experienced this?
Second question - When I accelerate, the RPM goes up high which is fine, but when I let off the gas pedal, the RPM remains high for a long period of time. Is that normal?
I really appreciate your input.
Second question - When I accelerate, the RPM goes up high which is fine, but when I let off the gas pedal, the RPM remains high for a long period of time. Is that normal?
I really appreciate your input.
Racer
Joined: Apr 2020
Posts: 425
Likes: 272
From: Cape Coral,FL
Did they do the triple flush and put in the new trans fluid or just repalce with the old trans fluid. It could be unrelated to the fluid as well I am not really sure I would take it back and tell them it didn't fix it see what they say. Do you still have a warranty or is this out of pocket.
The second issue isn't an issue sounds like it is performace shift if you hit the throttle really fast to the floor then let off it goes into performace shift keeps the rpms in the sweet spot. Basically the computer thinks you want to race. Try it next time you drive it will say performace shift on the dash. I have soler throttle controller and it seems to kick in performace shift at half throttle not full I accidently activate it at times.
The second issue isn't an issue sounds like it is performace shift if you hit the throttle really fast to the floor then let off it goes into performace shift keeps the rpms in the sweet spot. Basically the computer thinks you want to race. Try it next time you drive it will say performace shift on the dash. I have soler throttle controller and it seems to kick in performace shift at half throttle not full I accidently activate it at times.
Le Mans Master
Joined: May 1999
Posts: 6,516
Likes: 1,303
From: Windermere FL
There are a few things to do to help with the "jerk". You can check through a GM dealer if the car ever had TCM module updated with the latest software. I doubt you are under warranty still with a '15 so it will cost you big bucks to have them update it. But that will not completely eliminate the cold start Jerk. The full fix is replacement of some of the internal tranny guts which will be MAJOR bucks outside of warranty. I believe the issue is that there is something inside the tranny letting the fluid leak internally overnight and it jerks because it is waiting for the fluid to circulate and then POW! What I do is let the car idle for 30 seconds on first cold start and the jerk for mine is not present. If I am impatient, I get the jerk.
Welcome to the wonderful GM A8 auto
As far as the RPM staying high, that does not seem to be normal to me.
BTW - there is a sticky thread on top of this forum which has every single piece of information you could ever want on the A8 and all the wonderful issues.
Welcome to the wonderful GM A8 auto
As far as the RPM staying high, that does not seem to be normal to me.
BTW - there is a sticky thread on top of this forum which has every single piece of information you could ever want on the A8 and all the wonderful issues.
Last edited by Flame Red; Apr 2, 2021 at 10:43 AM.
Thread Starter
Intermediate
Joined: Nov 2015
Posts: 36
Likes: 0
Not sure about the triple flush. The service guy said they changed the trans fluid. I need to look into the performance shift. It takes a long time for the RPM to drop back down...almost nerve wrecking
Team Owner
Joined: Aug 2006
Posts: 25,105
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C6 of Year Finalist (appearance mods) 2019
Mine seems to hold revs a little until the transmission gets up to temp also.
Melting Slicks
Joined: Jun 2017
Posts: 2,568
Likes: 1,183
From: Conyers Georgia
There is a service bulletin for this delayed engagement.16-na-014. The triple flush will not fix this issue. It is the internal "stator" in the torque converter. After sitting for several hours the fluid drains from the TC back into the transmission. I had the stator replaced last year and it solved the problem. My car shield warranty covered the 4 grand price tag.
Thread Starter
Intermediate
Joined: Nov 2015
Posts: 36
Likes: 0
Thanks for the input. I will try to let the car idle for a while from now on until I figure out which route to take. If this is an issue with C7s, I wonder why its not in the service bulletins, like the issue with the leaking gas tanks on the C6s?
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Your second issue is normal - my 2014 A6 does the same thing and it shows performance shift activated (or something like that) on the dash cluster.
Instructor
Joined: Feb 2014
Posts: 227
Likes: 69
From: Hawaii
This is sometimes called the "garage shift" and the transmission sometimes does not need new parts, just a relearn that can be done at any dealer
https://www.corvetteactioncenter.com...ents-1365.html
Also hold the right up shift paddle for a few seconds to exit performance shift mode and return to normal
https://www.corvetteactioncenter.com...ents-1365.html
Also hold the right up shift paddle for a few seconds to exit performance shift mode and return to normal
Last edited by AND0; Apr 7, 2021 at 04:46 PM.