Is this normal
Thread Starter
Racer
Joined: Jun 2012
Posts: 285
Likes: 10
Is this normal
Just hit 2000 miles on my 2015 automatic (not a z51 or z06) and decided to really step on it for the first time. Started off rolling at around 20 and then stepped on it, when the transmission shifted from 2nd to 3rd, it really shifted hard and made a terrible noise (like it wasn't fully in sync when it shifted). I then went and found some safe, backwoods, strait aways and found it did the same thing 3 out of 4 times.
Anyone have any ideas what may be causing this, or is this normal when the auto transmission shifts at around 5500. I don't experience this in normal or semi aggressive driving. The only other problem i have is if i'm on cruise control at around 60, the transmission shifts back and forth very frequently and a little hard at times.
Should I be concerned, and/or do you think this is just some minor adjustment that can be made by the dealer? Thanks for any ideas/suggestions you may have.
Anyone have any ideas what may be causing this, or is this normal when the auto transmission shifts at around 5500. I don't experience this in normal or semi aggressive driving. The only other problem i have is if i'm on cruise control at around 60, the transmission shifts back and forth very frequently and a little hard at times.
Should I be concerned, and/or do you think this is just some minor adjustment that can be made by the dealer? Thanks for any ideas/suggestions you may have.
Instructor
Joined: Dec 2014
Posts: 159
Likes: 1
I have a 2015 A8 Z51 but I only put 630 miles on it before putting it in storage. I think I have the same transmission as you. I hit my hard several times after break-in and I never experienced any of the things you're describing even when cruising. I think I'd have it checked out.
Team Owner
Joined: Sep 2005
Posts: 20,352
Likes: 568
From: Ventura County, Calif
I think what you are experiencing is the 100ms fuel cut off at WOT shifts. I'm saying this based on discussions of the 2014 A6. I haven't seen anyone discuss it similarly for the A8 yet. I'm only assuming the A8 is the same programming. (Yes I know about assuming. 
)
Here's just one example, basically posts 1 - 4:
https://www.corvetteforum.com/forums...ogramming.html
)Here's just one example, basically posts 1 - 4:
https://www.corvetteforum.com/forums...ogramming.html
Racer
Joined: May 2011
Posts: 437
Likes: 82
Just hit 2000 miles on my 2015 automatic (not a z51 or z06) and decided to really step on it for the first time. Started off rolling at around 20 and then stepped on it, when the transmission shifted from 2nd to 3rd, it really shifted hard and made a terrible noise (like it wasn't fully in sync when it shifted). I then went and found some safe, backwoods, strait aways and found it did the same thing 3 out of 4 times.
Anyone have any ideas what may be causing this, or is this normal when the auto transmission shifts at around 5500. I don't experience this in normal or semi aggressive driving. The only other problem i have is if i'm on cruise control at around 60, the transmission shifts back and forth very frequently and a little hard at times.
Should I be concerned, and/or do you think this is just some minor adjustment that can be made by the dealer? Thanks for any ideas/suggestions you may have.
Anyone have any ideas what may be causing this, or is this normal when the auto transmission shifts at around 5500. I don't experience this in normal or semi aggressive driving. The only other problem i have is if i'm on cruise control at around 60, the transmission shifts back and forth very frequently and a little hard at times.
Should I be concerned, and/or do you think this is just some minor adjustment that can be made by the dealer? Thanks for any ideas/suggestions you may have.
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Burning Brakes
Joined: Mar 2013
Posts: 1,135
Likes: 14
Just a thought here...what was the outside temperature?
If cold, you could be experiencing wheel hop after the abrupt (but probably normal) gear change due to summer compound tires in cold weather.
Again, just a thought.
If cold, you could be experiencing wheel hop after the abrupt (but probably normal) gear change due to summer compound tires in cold weather.
Again, just a thought.
Melting Slicks
Joined: Jan 2001
Posts: 2,996
Likes: 304
From: MOORESVILLE NC
Take your C7 to the local Drag Strip. Give it hell and record what happens on a I-phone. I'm curious also. I have nowhere to do what you are doing without possibly wrecking my car. I know it goes fast, I don't need to punch it to know.
Melting Slicks
Joined: May 2013
Posts: 2,416
Likes: 805
From: Argyle, Texas
I have the A8 with 5000ish miles on it and havent ever heard anything that resembles what you describe. WOT pulls from a dead stop have a bit of wheelspin through about 3rd gear but the sound it makes is wonderful and in no way sounds like something out of the ordinary. There is a bit traction control restraint but it just sounds like the car holds the revs steady for a second while the tires find grip and then it lets go. Ive been running my C7 pretty hard since day 1 mile 1, with more than few launch controlled pulls and havent had any issue with the A8 other than the neutral into drive lurch that is due to how it has learned to shift from my aggressive driving.
Thread Starter
Racer
Joined: Jun 2012
Posts: 285
Likes: 10
Just hit 2000 miles on my 2015 automatic (not a z51 or z06) and decided to really step on it for the first time. Started off rolling at around 20 and then stepped on it, when the transmission shifted from 2nd to 3rd, it really shifted hard and made a terrible noise (like it wasn't fully in sync when it shifted). I then went and found some safe, backwoods, strait aways and found it did the same thing 3 out of 4 times.
Anyone have any ideas what may be causing this, or is this normal when the auto transmission shifts at around 5500. I don't experience this in normal or semi aggressive driving. The only other problem i have is if i'm on cruise control at around 60, the transmission shifts back and forth very frequently and a little hard at times.
Should I be concerned, and/or do you think this is just some minor adjustment that can be made by the dealer? Thanks for any ideas/suggestions you may have.
Anyone have any ideas what may be causing this, or is this normal when the auto transmission shifts at around 5500. I don't experience this in normal or semi aggressive driving. The only other problem i have is if i'm on cruise control at around 60, the transmission shifts back and forth very frequently and a little hard at times.
Should I be concerned, and/or do you think this is just some minor adjustment that can be made by the dealer? Thanks for any ideas/suggestions you may have.
update - took the car out again today and discovered the following . If I put the petal to the floor, when the car shifts from 2nd to third, and when rpm drops from 5500 to 4000 rpm into third, that's when it sounds like the transmission is about to fall out of the car. However, if I put the petal about an inch from the floor when accelerating, and at about the same rate of acceleration, the shift from 2nd to 3rd is smooth without the noise.
Wondering, if the car is switching to competition mode at the same time I'm picking up third and that is what is causing the issue? Any other ideas?
Melting Slicks
Joined: May 2013
Posts: 2,416
Likes: 805
From: Argyle, Texas
That doesnt sound normal to me. I have never heard the transmission do anything even remotelylike what you describe. Pedal tothe floor launches in my A8 C7 are pretty smooth and the only things you hear is the tires trying to get traction and the engine note change between shifts. Perhaps you might be able to get someone to video your car during launches to give us all a better idea of the noise you are talking about. I would be at the service center if I heard anything sound like its "falling out of the car". In my experience the A8 is buttery smooth, and with WoT shifting is aggresive and immediate with no real fuss.
Drifting
Joined: Mar 2013
Posts: 1,329
Likes: 5
The day I drove mine out of the showroom I did have one nasty *** head snapping shift but after that one it seemed OK. Mine is also in storage now so once the weather gets better in a month or so we will see what happens.
Advanced
Joined: Sep 2014
Posts: 78
Likes: 6
Just hit 2000 miles on my 2015 automatic (not a z51 or z06) and decided to really step on it for the first time. Started off rolling at around 20 and then stepped on it, when the transmission shifted from 2nd to 3rd, it really shifted hard and made a terrible noise (like it wasn't fully in sync when it shifted). I then went and found some safe, backwoods, strait aways and found it did the same thing 3 out of 4 times.
Anyone have any ideas what may be causing this, or is this normal when the auto transmission shifts at around 5500. I don't experience this in normal or semi aggressive driving. The only other problem i have is if i'm on cruise control at around 60, the transmission shifts back and forth very frequently and a little hard at times.
Should I be concerned, and/or do you think this is just some minor adjustment that can be made by the dealer? Thanks for any ideas/suggestions you may have.
Anyone have any ideas what may be causing this, or is this normal when the auto transmission shifts at around 5500. I don't experience this in normal or semi aggressive driving. The only other problem i have is if i'm on cruise control at around 60, the transmission shifts back and forth very frequently and a little hard at times.
Should I be concerned, and/or do you think this is just some minor adjustment that can be made by the dealer? Thanks for any ideas/suggestions you may have.
Safety Car
Joined: Jun 2008
Posts: 4,610
Likes: 427
From: USA
When WOT and shifting, my A8 shows "Performance shift active" on the DIC. When it shifts at high RPMs it makes an awesome sound, but like nothing I've heard before. It's somewhat of an exotic sound to me when it shifts at high RPM and WOT. It doesn't sound like something is wrong though as you are describing.
Thread Starter
Racer
Joined: Jun 2012
Posts: 285
Likes: 10
When u put your foot in it give it just a little gas to get off the V-4 mode before stomping on it, or it will do it every time.. that banging your hearing is the engine transitioning to V-8 and downshifting to a lower gear at the same time.. Sounds like hell... Mine does it every time.. Stomp on it when in V-8 and it just shifts the tranny only with just a kick in the ***, and no bang stutter.
Safety Car
Joined: Jun 2008
Posts: 4,610
Likes: 427
From: USA
Yes, track mode should keep it in v8 mode the entire time. Mine just makes a really loud "bark" sound when shifting, but I think it sounds mean as hell!
Race Director
Joined: Apr 2009
Posts: 10,581
Likes: 252
From: SE TEX
When WOT and shifting, my A8 shows "Performance shift active" on the DIC. When it shifts at high RPMs it makes an awesome sound, but like nothing I've heard before. It's somewhat of an exotic sound to me when it shifts at high RPM and WOT. It doesn't sound like something is wrong though as you are describing.
