[Z06] GM response to LS7 valve guide issue summary confirmed
08-31-2012, 05:52 PM
#21
Burning Brakes
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I have an 09z with 7k that will be out of powertrain warranty next September. There are probably many out there with not much warranty left and low miles such as mine.
08-31-2012, 06:19 PM
#22
Team Owner
I know this summary is important information for all of us, but it still doesn't explain the high failure rate between '06-'08 model years. Lots of Zs of those years dropped valves, even stock.
Therefore, the information provided only tells us that '09-'11 years were affected with a QC issue; however, those are the years that we really don't see failure in, and I know low production numbers have a significant influence on that.
Still no explanation for the failures of early Z06s, therefore, I can assume there is no issue with them and all failures were just irrelevant according to this statement by GM.
Therefore, the information provided only tells us that '09-'11 years were affected with a QC issue; however, those are the years that we really don't see failure in, and I know low production numbers have a significant influence on that.
Still no explanation for the failures of early Z06s, therefore, I can assume there is no issue with them and all failures were just irrelevant according to this statement by GM.
08-31-2012, 06:22 PM
#23
08-31-2012, 06:32 PM
#24
Le Mans Master
Thread Starter
If you have an 09, you're good until 14.
Here's the story --
If your car falls outside of warranty it doesn't mean you are susceptible to taking it on the chin. GM puts a lot of stock into extending goodwill to the customer. If you have a car that has elapsed the time period stated in the warranty but have very low mileage, you can still be a candidate for warranty work.
How?
This is handled through the dealers. If you feel your car is making a very loud rattle/chatter (not a tick-tick) you would take your car to the dealer. It's hard to explain what to listen for, but it's one of those things that you just know just isn't right. If you're in doubt, take it in. Right now there shouldn't be any cars that fall outside the warranty window as this is relevant to 09,10 and early 11 (Feb) models. The dealers have the authority to go to bat for a customer in cases like you are asking about here, a very low mileage car that may have this issue. After explaining your issue, the dealer may inform you that the work will have to be paid by you in the event there is no warranty work awarded. If so, you may have to decide if it's worth the few bucks to have them pull a cover and check for you, I think it would be. They will compare your car to others if available. If no issue is found, it would be advisable to have the service writer denote in your history that you did indeed bring your car in for such inspection in case something happens in the future.
08-31-2012, 06:35 PM
#25
I know this summary is important information for all of us, but it still doesn't explain the high failure rate between '06-'08 model years. Lots of Zs of those years dropped valves, even stock.
Therefore, the information provided only tells us that '09-'11 years were affected with a QC issue; however, those are the years that we really don't see failure in, and I know low production numbers have a significant influence on that.
Still no explanation for the failures of early Z06s, therefore, I can assume there is no issue with them and all failures were just irrelevant according to this statement by GM.
Therefore, the information provided only tells us that '09-'11 years were affected with a QC issue; however, those are the years that we really don't see failure in, and I know low production numbers have a significant influence on that.
Still no explanation for the failures of early Z06s, therefore, I can assume there is no issue with them and all failures were just irrelevant according to this statement by GM.
I agree that these thoughts by GM only reflects issues caused by the the 09-11 milling/geometry issues and not the other valve guide wear issue folks are concerned about.
And for that issue, I don't think that issue is isolated to 06-08s and I think this affected every MY. On a car with mods that exasperate the issue, every year fails the same way, so I'm led to believe there have been no changes, and over time the newer cars will eventually fail when stock. I do believe that the low production numbers and the fact they are newer are likely the reason why we haven't heard wide spread reports. Debatable reports of 09-10s have started to trickle in and I suspect we'll see more as time goes on.
08-31-2012, 06:50 PM
#26
Le Mans Master
Thread Starter
As far as modded cars, that's Pandora's box with countless permutations of possibilities from bolt-on, suspension, tires, et al so I'm not going to touch it. I will say this, there are plenty of 'mild' mods available that can in fact expedite engine failure that many owners may not realize. If you're going to mod, go big!
08-31-2012, 06:58 PM
#28
Stay tuned guys...
As far as modded cars, that's Pandora's box with countless permutations of possibilities from bolt-on, suspension, tires, et al so I'm not going to touch it. I will say this, there are plenty of 'mild' mods available that can in fact expedite engine failure that many owners may not realize. If you're going to mod, go big!
As far as modded cars, that's Pandora's box with countless permutations of possibilities from bolt-on, suspension, tires, et al so I'm not going to touch it. I will say this, there are plenty of 'mild' mods available that can in fact expedite engine failure that many owners may not realize. If you're going to mod, go big!
BTW, that is sort of my point in terms of the overall exhaust valve issue (not the 09-11 milling problem). I agree that engine mods can exasperate the issue and because they fail the same exact way on early cars vs late cars, that nothing was actually done to resolve it for any of the years.
This 09-11 milling issue is just another root cause on top of the existing guide wear issue.
Last edited by Jawnathin; 08-31-2012 at 07:00 PM.
08-31-2012, 07:20 PM
#29
Thanks Mike, I'll stay tuned and I'm looking forward to learning more. I appreciate your insights.
BTW, that is sort of my point in terms of the overall exhaust valve issue (not the 09-11 milling problem). I agree that engine mods can exasperate the issue and because they fail the same exact way on early cars vs late cars, that nothing was actually done to resolve it for any of the years.
This 09-11 milling issue is just another root cause on top of the existing guide wear issue.
BTW, that is sort of my point in terms of the overall exhaust valve issue (not the 09-11 milling problem). I agree that engine mods can exasperate the issue and because they fail the same exact way on early cars vs late cars, that nothing was actually done to resolve it for any of the years.
This 09-11 milling issue is just another root cause on top of the existing guide wear issue.
http://forums.corvetteforum.com/c6-z...-restored.html
08-31-2012, 07:30 PM
#30
Le Mans Master
Thread Starter
08-31-2012, 07:51 PM
#31
Le Mans Master
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St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17,'22-'23
Good points.
I agree that these thoughts by GM only reflects issues caused by the the 09-11 milling/geometry issues and not the other valve guide wear issue folks are concerned about.
And for that issue, I don't think that issue is isolated to 06-08s and I think this affected every MY. On a car with mods that exasperate the issue, every year fails the same way, so I'm led to believe there have been no changes, and over time the newer cars will eventually fail when stock. I do believe that the low production numbers and the fact they are newer are likely the reason why we haven't heard wide spread reports. Debatable reports of 09-10s have started to trickle in and I suspect we'll see more as time goes on.
I agree that these thoughts by GM only reflects issues caused by the the 09-11 milling/geometry issues and not the other valve guide wear issue folks are concerned about.
And for that issue, I don't think that issue is isolated to 06-08s and I think this affected every MY. On a car with mods that exasperate the issue, every year fails the same way, so I'm led to believe there have been no changes, and over time the newer cars will eventually fail when stock. I do believe that the low production numbers and the fact they are newer are likely the reason why we haven't heard wide spread reports. Debatable reports of 09-10s have started to trickle in and I suspect we'll see more as time goes on.
08-31-2012, 07:58 PM
#32
It is good to know that my efforts did not go unnoticed.
08-31-2012, 08:50 PM
#33
Le Mans Master
I know this summary is important information for all of us, but it still doesn't explain the high failure rate between '06-'08 model years. Lots of Zs of those years dropped valves, even stock.
Therefore, the information provided only tells us that '09-'11 years were affected with a QC issue; however, those are the years that we really don't see failure in, and I know low production numbers have a significant influence on that.
Still no explanation for the failures of early Z06s, therefore, I can assume there is no issue with them and all failures were just irrelevant according to this statement by GM.
Therefore, the information provided only tells us that '09-'11 years were affected with a QC issue; however, those are the years that we really don't see failure in, and I know low production numbers have a significant influence on that.
Still no explanation for the failures of early Z06s, therefore, I can assume there is no issue with them and all failures were just irrelevant according to this statement by GM.
08-31-2012, 08:59 PM
#34
Le Mans Master
08-31-2012, 09:30 PM
#36
Safety Car
Unless we have build dates or a number of failures GM has seen we are still in a guessing game as to if you could fail or not. All it would mean is GM is admitting an issue for some and/or all Z06s but those people out of warranty are SOL
08-31-2012, 09:37 PM
#37
Pro
I bought an 09Z new 24 months ago. There is some ticking at low RPM. The dealer I use had that info placed in the service records in case I have a problem at a latter date.
08-31-2012, 11:09 PM
#38
Le Mans Master
I have heard that the low rpm ticking could be normal for the engine just like the first gear marbles in a can rattle due to torque tube vibration is normal for the car. It really depends on how loud it is. I would think that valvetrain noise as discussed here would exist at all rpm but I could be wrong. Hopefully someone with more experience will answer this.
08-31-2012, 11:35 PM
#39
Safety Car
Kinda funny that only cars still under warranty are mentioned as the problem units. I imagine GM would open quite a can of worms to admit the problem has been around since the 2006MY.
09-01-2012, 12:01 AM
#40
Melting Slicks
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Many of you know my close relationship with Team Corvette and how accurate and truthful my posts are -- those that don't will have to decide for yourself what you do, or do not want to believe. Unfortunately in this high tech age I concede anyone with a keyboard can be a self-proclaimed expert so it's tough to filter out all the misinformation these days.
JVP posted this information in another thread, but it was buried after over 500 posts, so this is for the benefit of many who gave up on that thread, or never saw it.
I was going to post this some time ago but refrained. The recent hysteria over the valve guide issue has been inconceivable as it's come to a point where any failure or issue with the car, even a flat tire was blamed on valve guides.
I posted to substantiate this information is correct.
Furthermore;
If a car makes it through even a fraction of the 100k mile warranty, it is built properly and will have a complete service life.
As far as excessive noise mentioned, it doesn't have to be excessive but more-so not normal or unusual.
If your car is under warranty stop fretting a go enjoy each drive.
If your car is modified you run the risk of spending your own dime for repair, no news here.
There are legitimate failures as with any machine, but there are a countless number of failures that occur due to owner abuse, whether realized or not. In conjunction with the team, I will be providing forthcoming preventative maintenance tips.
The Z06 is a street car, not a race car and if you drive it as such, you have to prep it as such.
Lastly:
Katech has chimed in multiple times with helpful information. If there is an issue, it's not a matter of simply replacing the valves (edit-I had guides here originally and didn't catch the error before posting) like many have suggested, there's more to it and Katech's approach is correct. I'm not singling Katech out as the only shop credible as I know there are other builders, but merely the only shop I can personally vouch for and one that my GM friends approve.
Hopefully this will put a rest to the LS7 paranoia.
I will follow up with any additional questions posed here.
Mike
JVP posted this information in another thread, but it was buried after over 500 posts, so this is for the benefit of many who gave up on that thread, or never saw it.
I was going to post this some time ago but refrained. The recent hysteria over the valve guide issue has been inconceivable as it's come to a point where any failure or issue with the car, even a flat tire was blamed on valve guides.
I posted to substantiate this information is correct.
Furthermore;
If a car makes it through even a fraction of the 100k mile warranty, it is built properly and will have a complete service life.
As far as excessive noise mentioned, it doesn't have to be excessive but more-so not normal or unusual.
If your car is under warranty stop fretting a go enjoy each drive.
If your car is modified you run the risk of spending your own dime for repair, no news here.
There are legitimate failures as with any machine, but there are a countless number of failures that occur due to owner abuse, whether realized or not. In conjunction with the team, I will be providing forthcoming preventative maintenance tips.
The Z06 is a street car, not a race car and if you drive it as such, you have to prep it as such.
Lastly:
Katech has chimed in multiple times with helpful information. If there is an issue, it's not a matter of simply replacing the valves (edit-I had guides here originally and didn't catch the error before posting) like many have suggested, there's more to it and Katech's approach is correct. I'm not singling Katech out as the only shop credible as I know there are other builders, but merely the only shop I can personally vouch for and one that my GM friends approve.
Hopefully this will put a rest to the LS7 paranoia.
I will follow up with any additional questions posed here.
Mike
So before 2009 there have been no problems with dropped valves? Really?
"If a car makes it through even a fraction of the 100k mile warranty, it is built properly and will have a complete service life."
Define fraction 10%, 20% or is it 50%. There are cars with low miles dropping valves including 06' through 08's. I am having a hard time believing this.
Last edited by achilds; 09-01-2012 at 12:04 AM.