Unusual Problem
Thread Starter
Instructor
Joined: Oct 2000
Posts: 103
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From: Orcutt CA
Unusual Problem
As I am driving my 2019 A8 GS at a steady speed, I feel a thump and the revs jumps 100 - 200rpm then within a second or so, it drops back to the previous speed. This is cycling is continuous and happens in v8 or v4 mode, on cruise control or not. The only difference is that in v4 mode, the thump seems to be stronger, but does not force the transition to v8 mode. It will go away if I change speed, but then resumes once I am at the new speed. From what I have read, this seems to be different than the shudder others have reported. A club member has a new to him 2016 that is doing the same thing. Any suggestions on what it might be?
Thanks in advance for any help.
Thanks in advance for any help.
Tech Contributor
Joined: Oct 1999
Posts: 41,037
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From: Charlotte, NC (formerly Endicott, NY)
When the rpm increases by that amount that means the Torque Convertor Clutch has disengaged and you see the inherent slippage of the torque converter which is natural on any slushbox automatic with a lock-up torque converter. The noise and feel indicate you may need the triple flush to try and smooth out the operation so it isn't noticeable.
Bill
Bill
Team Owner
Joined: Sep 2000
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From: Far NW 'burbs of Chicago
St. Jude Donor '13
The 2019 cars came with the newest tranny fluid, so a flush will be expensive (if not under powertrain warranty) and may not fix the problem.
Good luck to you!
Good luck to you!
Le Mans Master
Joined: Mar 2016
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From: 2019 CMG Z06
Not so Sir, at least not all. 19 production started very early. Cars made AFTER 2/1/19 received the correct Mobil1 fluid. Prior production date 19s still had the old fluid, hence OP's production date is key
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It would be worth the time to see when your car was built ad whether or not the triple flush was ever done.
Pro
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As I am driving my 2019 A8 GS at a steady speed, I feel a thump and the revs jumps 100 - 200rpm then within a second or so, it drops back to the previous speed. This is cycling is continuous and happens in v8 or v4 mode, on cruise control or not. The only difference is that in v4 mode, the thump seems to be stronger, but does not force the transition to v8 mode. It will go away if I change speed, but then resumes once I am at the new speed. From what I have read, this seems to be different than the shudder others have reported. A club member has a new to him 2016 that is doing the same thing. Any suggestions on what it might be?
Thanks in advance for any help.
Thanks in advance for any help.
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Melting Slicks
Joined: Feb 2018
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From: North Texas
Note:
Transmissions built after 2/19 had the new fluid. Just because the door sticker build date is after 2/19 that does not always mean the trans was. There is a code label on the trans itself that states its build date. If the date is after 2/19 you have the new fluid.
Transmissions built after 2/19 had the new fluid. Just because the door sticker build date is after 2/19 that does not always mean the trans was. There is a code label on the trans itself that states its build date. If the date is after 2/19 you have the new fluid.
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Note:
Transmissions built after 2/19 had the new fluid. Just because the door sticker build date is after 2/19 that does not always mean the trans was. There is a code label on the trans itself that states its build date. If the date is after 2/19 you have the new fluid.
Transmissions built after 2/19 had the new fluid. Just because the door sticker build date is after 2/19 that does not always mean the trans was. There is a code label on the trans itself that states its build date. If the date is after 2/19 you have the new fluid.
https://www.corvetteforum.com/forums...post1605125825
Le Mans Master
Joined: Mar 2016
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From: 2019 CMG Z06
Advanced
Joined: Jun 2021
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I was told by my local Chevy dealership that this item is not covered under your powertrain warranty and that this is only ever covered under your 3year/36k mile warranty....if you have gotten it covered under powertrain please let me know how.
Racer
Joined: Jan 2020
Posts: 426
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From: Boston
That seems odd as it’s the tranny and I’d think that’s a powertrain warranty issue. I have a June 19 GS so I was never able to do the 3 flush so I just replaced my filter after my first year and a half of ownership. But would recommend anyone who has an A8 try for the triple flush and if denied get it done or a filter and flush. Even with the “good fluid” I noticed an improvement in shifts.
Melting Slicks
Joined: Aug 2017
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From: Massachusetts
I wanted the triple flush under my extended 5/60 warranty and was also told it was not covered. The service-writer said it is treated as a maintenance issue. I have heard that many have had the service covered under warranty. Squeaky wheel gets the oil.
Le Mans Master
Joined: Mar 2016
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From: 2019 CMG Z06
I suppose dealers make up their own rules if they don’t “feel” like doing the work that day. GM stating that “if a customer complains of a shudder, you don’t have to replicate the problem, just do a triple flush with the new fluid” is not maintenance, at least as far as I’m concerned. I had 2 friends, one with a 17 Z, other with a 17 GS, both get this done under the powertrain warranties.
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Sounds like you will need the triple flush, whether it's on your dime or not is the question
Advanced
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I suppose dealers make up their own rules if they don’t “feel” like doing the work that day. GM stating that “if a customer complains of a shudder, you don’t have to replicate the problem, just do a triple flush with the new fluid” is not maintenance, at least as far as I’m concerned. I had 2 friends, one with a 17 Z, other with a 17 GS, both get this done under the powertrain warranties.