The dreaded "shudder", or something else?
Thread Starter
Pro
Joined: May 2006
Posts: 595
Likes: 84
From: Colonial Beach Virginia
The dreaded "shudder", or something else?
Just bought a pristine 2016 Z06 with 22k miles. All service records, etc appear to be available. I was not sure what to look for with the shudder issues with the A8, so I installed a Range device to eliminate this potential issue. Lately, I have been taking it on longer and longer drives and I started notice a strange harmonic when at constant RPM/Speed that comes and goes regularly. No shudder or issues seen when shifting, only this strange harmonic/vibration when at highway speeds. Is this part of the shudder issue where I should get the triple-flush done? Or likely something else? Is the shudder only seen during shifts?
Thanks!
Thanks!
Last edited by Redhook98; Nov 26, 2024 at 05:19 PM.
Le Mans Master
Joined: Oct 2014
Posts: 8,673
Likes: 2,728
From: Atlanta GA
Anything that rotates can setup a harmonic vibration, I had never had the shudder, I had a new set of tires put on and had then ROAD FORCED balanced. I jumped up on the highway to make sure I had no vibrations and guess what ... I had the same rhythmic vibration that you are describing
I drove right back to Discount, and they had to redo the balancing 2 more times with the last one being done as a BULLSEYE balance .... it's been 3 years since that day, and I do not have any vibration
This is the exact reason what so many people bash the A8, they complain about a vibration and the dealers just automatically default to do the trans flush with no diagnosis being done at all ... then when the flush does not fix the problem, the customer bashes the transmission
This was the reason why originally GM required a dealer to do a PICO test as that will pinpoint what is causing the vibration, not sure why they relaxed that requirement
Good luck and keep us posted
Dave
I drove right back to Discount, and they had to redo the balancing 2 more times with the last one being done as a BULLSEYE balance .... it's been 3 years since that day, and I do not have any vibration
This is the exact reason what so many people bash the A8, they complain about a vibration and the dealers just automatically default to do the trans flush with no diagnosis being done at all ... then when the flush does not fix the problem, the customer bashes the transmission
This was the reason why originally GM required a dealer to do a PICO test as that will pinpoint what is causing the vibration, not sure why they relaxed that requirement
Good luck and keep us posted
Dave
Burning Brakes
Joined: Jun 2018
Posts: 756
Likes: 172
From: SC
Anything that rotates can setup a harmonic vibration, I had never had the shudder, I had a new set of tires put on and had then ROAD FORCED balanced. I jumped up on the highway to make sure I had no vibrations and guess what ... I had the same rhythmic vibration that you are describing
I drove right back to Discount, and they had to redo the balancing 2 more times with the last one being done as a BULLSEYE balance .... it's been 3 years since that day, and I do not have any vibration
This is the exact reason what so many people bash the A8, they complain about a vibration and the dealers just automatically default to do the trans flush with no diagnosis being done at all ... then when the flush does not fix the problem, the customer bashes the transmission
This was the reason why originally GM required a dealer to do a PICO test as that will pinpoint what is causing the vibration, not sure why they relaxed that requirement
Good luck and keep us posted
Dave
I drove right back to Discount, and they had to redo the balancing 2 more times with the last one being done as a BULLSEYE balance .... it's been 3 years since that day, and I do not have any vibration
This is the exact reason what so many people bash the A8, they complain about a vibration and the dealers just automatically default to do the trans flush with no diagnosis being done at all ... then when the flush does not fix the problem, the customer bashes the transmission
This was the reason why originally GM required a dealer to do a PICO test as that will pinpoint what is causing the vibration, not sure why they relaxed that requirement
Good luck and keep us posted
Dave
Race Director
Joined: Oct 2004
Posts: 13,598
Likes: 1,353
From: Home of the VOLS ! Knoxville, TN. Tennessee
St. Jude Donor '11-'12-'13, '15, '16-'17-'18-'19
I just had the triple flush done. When you have the shudder, you can't miss it. It's very pronounced.
I know of rhythmic vibrations. I have had them before. They're not shudders.
My shudders happened only on shifting and never while cruising. Mine would happen when you downshift from 7 or 8 to a 4,5, or 6 to accelerate.
You need a road force balance.
I know of rhythmic vibrations. I have had them before. They're not shudders.
My shudders happened only on shifting and never while cruising. Mine would happen when you downshift from 7 or 8 to a 4,5, or 6 to accelerate.
You need a road force balance.
Burning Brakes
Joined: Jun 2018
Posts: 756
Likes: 172
From: SC
I just had the triple flush done. When you have the shudder, you can't miss it. It's very pronounced.
I know of rhythmic vibrations. I have had them before. They're not shudders.
My shudders happened only on shifting and never while cruising. Mine would happen when you downshift from 7 or 8 to a 4,5, or 6 to accelerate.
You need a road force balance.
I know of rhythmic vibrations. I have had them before. They're not shudders.
My shudders happened only on shifting and never while cruising. Mine would happen when you downshift from 7 or 8 to a 4,5, or 6 to accelerate.
You need a road force balance.
Team Owner
Joined: Sep 2010
Posts: 32,164
Likes: 4,620
45 years ago I bought a new 1980 Lincoln Town Car that had the new "4th gear" Overdrive. After a few tens of thousands of miles, it developed a shudder when shifting into overdrive. But not all the time. The car would buck like a bronco, violently. Nothing came of it though. I would just coast by taking my foot off the gas. And it would seem to heal its violent eruptions of bucking, and I carry on my highway drive.
Never addressed it with a Lincoln dealer, and never had a breakdown. Just kept driving it to 286K in 16 years .
Never addressed it with a Lincoln dealer, and never had a breakdown. Just kept driving it to 286K in 16 years .
Last edited by Skid Row Joe; Nov 27, 2024 at 04:51 PM.
Instructor
Joined: Apr 2018
Posts: 198
Likes: 102
From: Allegheny National Forest
Just bought a pristine 2016 Z06 with 22k miles. All service records, etc appear to be available. I was not sure what to look for with the shudder issues with the A8, so I installed a Range device to eliminate this potential issue. Lately, I have been taking it on longer and longer drives and I started notice a strange harmonic when at constant RPM/Speed that comes and goes regularly. No shudder or issues seen when shifting, only this strange harmonic/vibration when at highway speeds. Is this part of the shudder issue where I should get the triple-flush done? Or likely something else? Is the shudder only seen during shifts?
Thanks!
Thanks!
https://www.corvetteforum.com/forums...er-speeds.html
https://www.corvetteforum.com/forums...vibration.html
Thread Starter
Pro
Joined: May 2006
Posts: 595
Likes: 84
From: Colonial Beach Virginia
I just had the triple flush done. When you have the shudder, you can't miss it. It's very pronounced.
I know of rhythmic vibrations. I have had them before. They're not shudders.
My shudders happened only on shifting and never while cruising. Mine would happen when you downshift from 7 or 8 to a 4,5, or 6 to accelerate.
You need a road force balance.
I know of rhythmic vibrations. I have had them before. They're not shudders.
My shudders happened only on shifting and never while cruising. Mine would happen when you downshift from 7 or 8 to a 4,5, or 6 to accelerate.
You need a road force balance.
I am unfamiliar with a road force balance. Can any tire place do this? Tire have about 1200 miles on them. Michelin Pilot Super Sports.
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Burning Brakes
Joined: Jun 2018
Posts: 756
Likes: 172
From: SC
I just called my Chevrolet Cadillac dealer. The service advisor didn't know whst it was. She went away and came back a few minutes later and said it's $200.00 and regurlar balance is $125.00. But, how would i know if they really did it, is my question.
Race Director
Joined: Apr 2014
Posts: 10,447
Likes: 1,741
From: North Texas
Take a look at their balancing machine. If it doesn't have a roller that presses on the tire while it's being spun, then it isn't a road force balancer. As far as I can tell the Hunter Road Force Elite is the top of the line. They should be able to give you a road force score for each wheel/tire. The lower the better.
Le Mans Master
Joined: Oct 2014
Posts: 8,673
Likes: 2,728
From: Atlanta GA
I'm unfamiliar with Shudder but can imagine the feeling. i also have a rough idke and can also feel it at the end of a stop slmost like an out of round rotor. Also mine never auto downshifts into 2nd gear. Every time slowing to a stop, very slow stop, normal stop, it hangs in 3rd then 1st, then rough idle. So no way to stop without roug pulse feel. 23k miles and dealer said Bembro slotted disc are fine. 2018, Stingray, Z51.
As far as the rough idle , no corvette idles like a Cadillac... they all ide rough, proce u pay for performance
Dave
Le Mans Master
Joined: Oct 2014
Posts: 8,673
Likes: 2,728
From: Atlanta GA
I would run ... fast from that dealership , do you have a Discount Tire store or a Tire Discounters near by .... ?
Burning Brakes
Joined: Jun 2018
Posts: 756
Likes: 172
From: SC
I've owned 5 C5's and 1 C4. not one had a rough idle. I started my c5 today and it idols very smooth. This c7 is rough. And sometimes the rough idle is much worse than others. Idk . Any pointer on garage relearn Procedure is appreciated.
Le Mans Master
Joined: Oct 2014
Posts: 8,673
Likes: 2,728
From: Atlanta GA
Ok so clear adapts us simply disc battery for a few. I cant find Garage Relearn Procedure (only garage door opener relearn. Can you point me ?
I've owned 5 C5's and 1 C4. not one had a rough idle. I started my c5 today and it idols very smooth. This c7 is rough. And sometimes the rough idle is much worse than others. Idk . Any pointer on garage relearn Procedure is appreciated.
I've owned 5 C5's and 1 C4. not one had a rough idle. I started my c5 today and it idols very smooth. This c7 is rough. And sometimes the rough idle is much worse than others. Idk . Any pointer on garage relearn Procedure is appreciated.
Removing battery cables will not clear ADAPTS
See my post in this thread on what a garage relarn does
https://www.corvetteforum.com/forums...ogramming.html
As far as the rough Idle .....
The C7 makes 460 hp stock and will run a low 12 second , high 11 second quarter mile time which is crazy for a 3,600 pound car with full options ...your C4 does not even come close to making that much Horse Power and torque nor did the LS1 in your C5. Compaired to a C6 LS3 or a C7 LT1 they both were slugs
All this power comes at a cost .... a bit of a rough idle , it's the cam shaft and it's lift and duration that make the power. It's not your fathers Buick ......and never will be
Burning Brakes
Joined: Jun 2018
Posts: 756
Likes: 172
From: SC
U can't go a clear adapts or do a garage relearn without professional scan tool like GM's GDS2 , or a high dollar Autel .HP Tuners while not a true scan tool can do it also
Removing battery cables will not clear ADAPTS
See my post in this thread on what a garage relarn does
https://www.corvetteforum.com/forums...ogramming.html
As far as the rough Idle .....
The C7 makes 460 hp stock and will run a low 12 second , high 11 second quarter mile time which is crazy for a 3,600 pound car with full options ...your C4 does not even come close to making that much Horse Power and torque nor did the LS1 in your C5. Compaired to a C6 LS3 or a C7 LT1 they both were slugs
All this power comes at a cost .... a bit of a rough idle , it's the cam shaft and it's lift and duration that make the power. It's not your fathers Buick ......and never will be
Removing battery cables will not clear ADAPTS
See my post in this thread on what a garage relarn does
https://www.corvetteforum.com/forums...ogramming.html
As far as the rough Idle .....
The C7 makes 460 hp stock and will run a low 12 second , high 11 second quarter mile time which is crazy for a 3,600 pound car with full options ...your C4 does not even come close to making that much Horse Power and torque nor did the LS1 in your C5. Compaired to a C6 LS3 or a C7 LT1 they both were slugs
All this power comes at a cost .... a bit of a rough idle , it's the cam shaft and it's lift and duration that make the power. It's not your fathers Buick ......and never will be
Le Mans Master
Joined: Oct 2014
Posts: 8,673
Likes: 2,728
From: Atlanta GA
Burning Brakes
Joined: Jun 2018
Posts: 756
Likes: 172
From: SC
Le Mans Master
Joined: Oct 2014
Posts: 8,673
Likes: 2,728
From: Atlanta GA
Every Hi Performace car has its issues , get the garage relearn done , and scan it to make sure nothing else is wrong with it and it can be the most fun car you will ever own
Dave
Melting Slicks
Joined: Mar 2008
Posts: 2,453
Likes: 347
From: SC
Just bought a pristine 2016 Z06 with 22k miles. All service records, etc appear to be available. I was not sure what to look for with the shudder issues with the A8, so I installed a Range device to eliminate this potential issue. Lately, I have been taking it on longer and longer drives and I started notice a strange harmonic when at constant RPM/Speed that comes and goes regularly. No shudder or issues seen when shifting, only this strange harmonic/vibration when at highway speeds. Is this part of the shudder issue where I should get the triple-flush done? Or likely something else? Is the shudder only seen during shifts?
Thanks!
Thanks!
Burning Brakes
Joined: Jun 2018
Posts: 756
Likes: 172
From: SC