LS7 Failures in the Z/28's How Many? - Page 3 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Brutale arancia · 04-01-2019, 12:15 PM

Quote:

Originally Posted by richard grimsley

FYSA- I ended up having a odd noise from my Z at its 13k mile mark. Identification of concern after driving it for less than 4K miles as a DD. I took the Z in for concern. The heads were found to be of default and they were removed for repairs. Further investigation highly recommended, found that the bearings were shot (cam, cylinder walls, pistons and crank mains). The technical investigation department found the damage resulted to either the heads and or assembly. The GM warrenty did not cover due expiration. Thus, the engine had been thoroughly inspected and approved, the damage had not been discovered due to a the lack of investigation of internal components prior or at purchase, thus purchased with “GM certified-inspection”. From my overall perspective-crap happens. It’s a chance we take and or choose. We live every day, and only die once... we cannot take these materialistic items with us.

That's a sad story with a peaceful perspective. People around the world live in fear for their very lives. I have "the car, my pride and three pairs of jeans." (Dan Baird)

Fast02Z06 · 04-02-2019, 10:20 AM

Valve guides in the ls7 of any year (2006-2015) need to be addressed and there was never a fix tbh.

hjdca · 04-02-2019, 01:50 PM

Quote:

Originally Posted by Fast02Z06

Valve guides in the ls7 of any year (2006-2015) need to be addressed and there was never a fix tbh.

GM said it was a LS7 head supplier that was causing the Valve guide tolerance issue in the vettes and it was fixed by their QC investigation before the Z/28 came out. What evidence is there to dispute this ?

richard grimsley · 04-02-2019, 05:24 PM

Great progress, thus so far, positive progress.

j o n · 04-02-2019, 08:48 PM

Quote:

Originally Posted by hjdca

GM said it was a LS7 head supplier that was causing the Valve guide tolerance issue in the vettes and it was fixed by their QC investigation before the Z/28 came out. What evidence is there to dispute this ?

https://gwatneyperformance.com/ls7-v...-need-to-know/

joelster · 04-03-2019, 06:59 AM

Quote:

Originally Posted by j o n

https://gwatneyperformance.com/ls7-v...-need-to-know/

That is a great article you posted. Thank you! I'm still leaning towards the official word from Chevy, but if I ever tear into the engine, I will do these upgrades for piece of mind. Those T+D rockers look sweet. I have Jesel on my LT1 car, and they are bulletproof.

FWIW, I've talked to 2 shops that have experience working on Z/28's and both have said that the problem is 100% fixed on them. I honestly think we would have seen several more failures by now. I read stories of a few "failures" and some of them were unrelated issues. Hard to really determine an outcome.

ronchev · 04-03-2019, 07:48 AM

Quote:

Originally Posted by j o n

https://gwatneyperformance.com/ls7-v...-need-to-know/

Have not seen this one, Thanks for sharing jon

j o n · 04-03-2019, 07:53 AM

Quote:

Originally Posted by joelster

That is a great article you posted. Thank you! I'm still leaning towards the official word from Chevy, but if I ever tear into the engine, I will do these upgrades for piece of mind. Those T+D rockers look sweet. I have Jesel on my LT1 car, and they are bulletproof.

FWIW, I've talked to 2 shops that have experience working on Z/28's and both have said that the problem is 100% fixed on them. I honestly think we would have seen several more failures by now. I read stories of a few "failures" and some of them were unrelated issues. Hard to really determine an outcome.

I agree with the article's recommendation of the guides needing to be extended... .250 by their claims.

Increased valvetrain stability and decrease leverage/wear on the guide and valve

2014Z/28 · 04-03-2019, 08:50 AM

Quote:

Originally Posted by JR'S Z/28 Texas

Good Evening ALL! In the Z/28 LS7 how many engine failures are known? In Daily Drivers? Tracked Cars? Modified? Relating to Valve Train Problems? Other Problems? I know a lot of questions. I know the Z06-LS7 vette had some problems. Most was resolved in the LS7 of the Z/28. Just seeking some answers, For a New Potential Buyer that has a lot of concerns. Thanks JR

All the information that I have found is relating to the 427 corvettes engines that were produced between 2009 to 2011, that said... I have heard of valve spring issues with the Z/28 427 engines but I believe this was caused from improper downshifting in track applications. If anyone finds anything different please let me know.

Gbland60 · 04-05-2019, 01:53 PM

My question is this, out of all the Forum members on here that have had their heads removed and reworked or replaced with the heads and cam package why hasn't at least one of them asked the speed shop that they have doing the work on their engine to have company they send the oem heads to , to have the valve guides and valves mic'd and the results given to them and the owner posting the results with the mileage and type of driving that was done on those particular heads This is what baffles me. Was there an extra expense involved in doing all that and just didnt want to pay? Or did they think that it wasn't worthwhile letting the rest of the Forum members on here know what the results were to put this question into some sort of perspective because we all have questioned the data thats out there already. I just know that I'm not going to be one that openly gives my car to someone to replace the heads and not ask questions.I want to find out where the issue is if any and share that information with the rest of you. Sometimes I believe that we all just get caught up in our own little world that all we think about is going fast. I bought this car because I want to keep it. I want it to last.I want to use it for what it was designed for and if there's something that I need to address then I want to address it and I want to know what caused it and fix it right with the correct materials. not just relying on some Speed Shop to send my heads off and return them telling me your good to go now. I'm at almost 13k miles on mine, (and so far all is well), with factory powertrain warranty still in effect. Unless I just get totally impatient and I can't wait anymore, whenever my warranty is up it's guaranteed my heads are coming off and they will be mic'd and the results will be posted on this form unless there's a catastrophic failure between now and then that takes place. We have aluminum heads now no longer cast iron changes had to be made in the materials that they use to increase the longevity we all know this but make sure you use the proper metals when talking about valves and valve guides. Everyone knows when you increase lift you have to increase spring pressure and when you increase spring pressure you increase the side load on the stem so that was a good point that article pointed out in my opinion about increasing the links of the guides themselves. I don't come from a Big Town but there are some places that will actually sit down and talk to you for free and explain things that you may be concerned about. Maybe I'm Wrong maybe someone out there has the results that just hasn't posted them.but it sure would be nice to hear the findings. PS. I just hope no one out there takes this post the wrong way because I meant no ill by stating it. I just want to make sure that we all as owners of the 5th gen Z28 ( possibly the last) are not being misled for capital gains by some,because the issue was actually addressed and fixed at GM.

Biergut · 04-05-2019, 03:07 PM

Quote:

Originally Posted by Gbland60

My question is this, out of all the Forum members on here that have had their heads removed and reworked or replaced with the heads and cam package why hasn't at least one of them asked the speed shop that they have doing the work on their engine to have company they send the oem heads to , to have the valve guides and valves mic'd and the results given to them and the owner posting the results with the mileage and type of driving that was done on those particular heads This is what baffles me. Was there an extra expense involved in doing all that and just didnt want to pay? Or did they think that it wasn't worthwhile letting the rest of the Forum members on here know what the results were to put this question into some sort of perspective because we all have questioned the data thats out there already. I just know that I'm not going to be one that openly gives my car to someone to replace the heads and not ask questions.I want to find out where the issue is if any and share that information with the rest of you. Sometimes I believe that we all just get caught up in our own little world that all we think about is going fast. I bought this car because I want to keep it. I want it to last.I want to use it for what it was designed for and if there's something that I need to address then I want to address it and I want to know what caused it and fix it right with the correct materials. not just relying on some Speed Shop to send my heads off and return them telling me your good to go now. I'm at almost 13k miles on mine, (and so far all is well), with factory powertrain warranty still in effect. Unless I just get totally impatient and I can't wait anymore, whenever my warranty is up it's guaranteed my heads are coming off and they will be mic'd and the results will be posted on this form unless there's a catastrophic failure between now and then that takes place. We have aluminum heads now no longer cast iron changes had to be made in the materials that they use to increase the longevity we all know this but make sure you use the proper metals when talking about valves and valve guides. Everyone knows when you increase lift you have to increase spring pressure and when you increase spring pressure you increase the side load on the stem so that was a good point that article pointed out in my opinion about increasing the links of the guides themselves. I don't come from a Big Town but there are some places that will actually sit down and talk to you for free and explain things that you may be concerned about. Maybe I'm Wrong maybe someone out there has the results that just hasn't posted them.but it sure would be nice to hear the findings. PS. I just hope no one out there takes this post the wrong way because I meant no ill by stating it. I just want to make sure that we all as owners of the 5th gen Z28 ( possibly the last) are not being misled for capital gains by some,because the issue was actually addressed and fixed at GM.

MrRaZ28 · 04-05-2019, 04:26 PM

When I finally have some downtime from my full-time job and school, I plan on doing the tests without removing my heads. Shooting for first week in May. I have 54.5K miles on mine, with 7 track days of hard driving. I've put 11K on it since I bought it 1.5 years ago, and want to see what I find... I still have GMPP coverage, thankfully.

The_Raging_Bull · 04-10-2019, 12:53 AM

My 2 cents:
I have an 09 Z-06, and bought my Z/28 fully aware of this issue, Its simply put the most over worked set of threads and replies on CF. Specific to this subject; Hib Halverson covers what Chevy did to fix this issue in his article at the Corvette Action Center: on ages 18 to 22 of his article " The Ruthless Pursuit of Power: The Lucky Seven Edition - The Mystique of the 7 liter, 7000 rpm, LS7".

https://www.corvetteactioncenter.com...ine/index.html

That article can be found over at the Corvette Action center, and discusses the work that Chevy did in resolving superpolishing of the valve stem, as well as their efforts to perfect the alignment of the valves to valve guide geometry and 100% inspection. All related to ensuring the valve stem valve guide concentricity remains optimum.

My own fix in my 009 Z06? I did an American Heritage stage 4 upgrade, specifically using stud mounted roller rockers. This eliminates any side loading of the valve stem in the geometry of the stem-valve guide concentricity. This issue caused dropped valves in perhaps 100 to 150 Z06's in '09 to '11 corvette z06's where there issues. To my knowledge no LS7's have failed in Z/28's, so the hysteria on the CF doesn't apply here.

Prior to buying my Corvette Z06..which I obviously still have I read every thread and reply, there were ! 150 threads and !! 9000 replies..2 read them until I'd have enough and fully understood the issue.

DasBaldDog · 04-10-2019, 07:05 AM

Quote:

Originally Posted by The_Raging_Bull

My 2 cents:
I have an 09 Z-06, and bought my Z/28 fully aware of this issue, Its simply put the most over worked set of threads and replies on CF. Specific to this subject; Hib Halverson covers what Chevy did to fix this issue in his article at the Corvette Action Center: on ages 18 to 22 of his article " The Ruthless Pursuit of Power: The Lucky Seven Edition - The Mystique of the 7 liter, 7000 rpm, LS7".

https://www.corvetteactioncenter.com...ine/index.html

That article can be found over at the Corvette Action center, and discusses the work that Chevy did in resolving superpolishing of the valve stem, as well as their efforts to perfect the alignment of the valves to valve guide geometry and 100% inspection. All related to ensuring the valve stem valve guide concentricity remains optimum.

My own fix in my 009 Z06? I did an American Heritage stage 4 upgrade, specifically using stud mounted roller rockers. This eliminates any side loading of the valve stem in the geometry of the stem-valve guide concentricity. This issue caused dropped valves in perhaps 100 to 150 Z06's in '09 to '11 corvette z06's where there issues. To my knowledge no LS7's have failed in Z/28's, so the hysteria on the CF doesn't apply here.

Prior to buying my Corvette Z06..which I obviously still have I read every thread and reply, there were ! 150 threads and !! 9000 replies..2 read them until I'd have enough and fully understood the issue.

Correct me if I'm wrong, but didn't Hib also say in updates to that article and other postings that they received NEW LS7 heads from Chevy made as late as 2016 that have valve guides out of spec?

Found it, see page 24. https://www.corvetteactioncenter.com...-engine24.html

I believe I've read other commentary by Hib expositing on the new heads and others he has seen that were similarly offensive.

04-02-2019, 05:24 PM	#32
richard grimsley GRIM Drives: 2015 Camaro Z/28 Join Date: May 2010 Location: Marlton, NJ. Posts: 158	My Z’s progress Great progress, thus so far, positive progress. Attached Images

04-10-2019, 12:53 AM	#41
The_Raging_Bull Raging Bull Reborn Drives: '09 CGM Z063LZ '15 RH Z/28 #0631 Join Date: Mar 2012 Location: Broken Arrow OK Posts: 765 View My Garage	My 2 cents: I have an 09 Z-06, and bought my Z/28 fully aware of this issue, Its simply put the most over worked set of threads and replies on CF. Specific to this subject; Hib Halverson covers what Chevy did to fix this issue in his article at the Corvette Action Center: on ages 18 to 22 of his article " The Ruthless Pursuit of Power: The Lucky Seven Edition - The Mystique of the 7 liter, 7000 rpm, LS7". https://www.corvetteactioncenter.com...ine/index.html That article can be found over at the Corvette Action center, and discusses the work that Chevy did in resolving superpolishing of the valve stem, as well as their efforts to perfect the alignment of the valves to valve guide geometry and 100% inspection. All related to ensuring the valve stem valve guide concentricity remains optimum. My own fix in my 009 Z06? I did an American Heritage stage 4 upgrade, specifically using stud mounted roller rockers. This eliminates any side loading of the valve stem in the geometry of the stem-valve guide concentricity. This issue caused dropped valves in perhaps 100 to 150 Z06's in '09 to '11 corvette z06's where there issues. To my knowledge no LS7's have failed in Z/28's, so the hysteria on the CF doesn't apply here. Prior to buying my Corvette Z06..which I obviously still have I read every thread and reply, there were ! 150 threads and !! 9000 replies..2 read them until I'd have enough and fully understood the issue. __________________ Toy 1 '15 RH Z/28 w/AC & Radio S/N 0631 Toy 2 '09 CGM Z06 3LZ My DD: '17 Ford Mustang GT Her DD: '14 F150 Ecoboost 3.5

04-02-2019, 10:20 AM	#30
Fast02Z06 Drives: 2018 ZL1 Join Date: Mar 2019 Location: Houston tx Posts: 144	Valve guides in the ls7 of any year (2006-2015) need to be addressed and there was never a fix tbh.

04-05-2019, 01:53 PM	#38
Gbland60 Drives: 2015 z28 Black w/ac #645 Join Date: Jan 2017 Location: Southeast Texas Posts: 337 View My Garage	My question is this, out of all the Forum members on here that have had their heads removed and reworked or replaced with the heads and cam package why hasn't at least one of them asked the speed shop that they have doing the work on their engine to have company they send the oem heads to , to have the valve guides and valves mic'd and the results given to them and the owner posting the results with the mileage and type of driving that was done on those particular heads This is what baffles me. Was there an extra expense involved in doing all that and just didnt want to pay? Or did they think that it wasn't worthwhile letting the rest of the Forum members on here know what the results were to put this question into some sort of perspective because we all have questioned the data thats out there already. I just know that I'm not going to be one that openly gives my car to someone to replace the heads and not ask questions.I want to find out where the issue is if any and share that information with the rest of you. Sometimes I believe that we all just get caught up in our own little world that all we think about is going fast. I bought this car because I want to keep it. I want it to last.I want to use it for what it was designed for and if there's something that I need to address then I want to address it and I want to know what caused it and fix it right with the correct materials. not just relying on some Speed Shop to send my heads off and return them telling me your good to go now. I'm at almost 13k miles on mine, (and so far all is well), with factory powertrain warranty still in effect. Unless I just get totally impatient and I can't wait anymore, whenever my warranty is up it's guaranteed my heads are coming off and they will be mic'd and the results will be posted on this form unless there's a catastrophic failure between now and then that takes place. We have aluminum heads now no longer cast iron changes had to be made in the materials that they use to increase the longevity we all know this but make sure you use the proper metals when talking about valves and valve guides. Everyone knows when you increase lift you have to increase spring pressure and when you increase spring pressure you increase the side load on the stem so that was a good point that article pointed out in my opinion about increasing the links of the guides themselves. I don't come from a Big Town but there are some places that will actually sit down and talk to you for free and explain things that you may be concerned about. Maybe I'm Wrong maybe someone out there has the results that just hasn't posted them.but it sure would be nice to hear the findings. PS. I just hope no one out there takes this post the wrong way because I meant no ill by stating it. I just want to make sure that we all as owners of the 5th gen Z28 ( possibly the last) are not being misled for capital gains by some,because the issue was actually addressed and fixed at GM.

04-05-2019, 04:26 PM	#40
MrRaZ28 @MrRaZ28 Drives: 2014 Z28 #80 Join Date: Oct 2009 Location: Cincinnati, OH Posts: 590 View My Garage	When I finally have some downtime from my full-time job and school, I plan on doing the tests without removing my heads. Shooting for first week in May. I have 54.5K miles on mine, with 7 track days of hard driving. I've put 11K on it since I bought it 1.5 years ago, and want to see what I find... I still have GMPP coverage, thankfully.