LS7 valve guide issue. Sharing my experience with potential buyers
06-15-2019, 06:28 PM
#1
LS7 valve guide issue. Sharing my experience with potential buyers
Hello CF forum,
i realize that this is a dead horse issue that has been beaten over and over again but I’m going to go ahead with it anyways. A read through enough posts on this topic im sure will leave most potential buyers confused as there seems to be a some difference of opinion. On one hand you have the usual horror stories, on the other you have the people who are saying they have 75k miles with no issue. I must admit myself I was a non believer, I bought my car with 12k miles on it and there was no noticeable engine noise or anything that seemed amiss. I was on the fence about even having my heads inspected but thanks to corvette forum I decided to go ahead and wow am I glad I did. Many of my valves exceeded the service limit for play by over 300% I went ahead and ordered the stage 4 heads from AHP and had a local shop install them. I must say AHP is a class act outfit, a pleasure to deal with and now my LS7 is running like a dream, it’s nice to take the car to redline without that looming fear of a potential valve drop. Below I will be posting videos of the play on my stock heads. My goal with this post is just to shed some more light on the topic for potential buyers, or current owners who’s cars are running “fine” I will say again that there was nothing to indicate issues with my motor before hand. I knew about the LS7 head issue but didn’t think it was as wide spread as the internet makes it out to be. Either I am just extremely unlucky, or it is definitely as bad as the hype leads to believe.
Kurtis
i realize that this is a dead horse issue that has been beaten over and over again but I’m going to go ahead with it anyways. A read through enough posts on this topic im sure will leave most potential buyers confused as there seems to be a some difference of opinion. On one hand you have the usual horror stories, on the other you have the people who are saying they have 75k miles with no issue. I must admit myself I was a non believer, I bought my car with 12k miles on it and there was no noticeable engine noise or anything that seemed amiss. I was on the fence about even having my heads inspected but thanks to corvette forum I decided to go ahead and wow am I glad I did. Many of my valves exceeded the service limit for play by over 300% I went ahead and ordered the stage 4 heads from AHP and had a local shop install them. I must say AHP is a class act outfit, a pleasure to deal with and now my LS7 is running like a dream, it’s nice to take the car to redline without that looming fear of a potential valve drop. Below I will be posting videos of the play on my stock heads. My goal with this post is just to shed some more light on the topic for potential buyers, or current owners who’s cars are running “fine” I will say again that there was nothing to indicate issues with my motor before hand. I knew about the LS7 head issue but didn’t think it was as wide spread as the internet makes it out to be. Either I am just extremely unlucky, or it is definitely as bad as the hype leads to believe.
Kurtis
Last edited by SparkyZ06; 06-15-2019 at 11:12 PM.
The following 2 users liked this post by SparkyZ06:
American Heritage (06-16-2019),
snampro (06-18-2019)
06-15-2019, 07:06 PM
#2
Safety Car
Kurtis, thank you for sharing in my mind there’s no doubt you have made the right move. Peace of mind is priceless
06-16-2019, 05:04 AM
#7
Le Mans Master
The hype is real, dealing with this issue is a fact of ownership; only the gamblers and closed-minded will do nothing.
Good move, enjoy the car.
Good move, enjoy the car.
Last edited by Dan_the_C5_Man; 06-17-2019 at 11:06 AM.
06-16-2019, 12:32 PM
#9
Mrzeta06
I bought mine with 17k in decide to modify cam it. Went with HORSE POWER ADDICT to do my work. They checked the valves said they were fine but for a peace of mind had them install there stage 2 heads which upgrade the valves etc. I rather spend the money then when the engine was apart already and enjoy her without worrying blowing up the engine. Mind you i dont drag race or road race yet lol. So besides opening her up in the highway she isnt beat on like a track car. Doing the correction is just protecting your investment. You did the right thing.
The following users liked this post:
HorsePowerAddicts (06-18-2019)
06-16-2019, 05:38 PM
#10
Burning Brakes
I put 55,000 miles on my Z and had the heads done - American Racing headers and exhaust (2") WCCH heads and a tune with Mighty Mouse catch can and a Air Raid CAI. No issues no problems and now it sounds and performs better. What a difference, mostly because it is better but also I don't have the nagging worry about the engine blowing up on me.
06-16-2019, 05:56 PM
#11
Instructor
Smart move by all that have addressed the head/valve issue. I was going to have my heads done before the extended warranty expired on my LS7, but time got away on me and about 2 weeks later the motor let loose while running at the Glen. GM helped me out some, but was still an expensive ordeal. Don't wait to address this issue, get it done and enjoy a really sweet motor with piece of mind.
06-16-2019, 10:51 PM
#12
Supporting Vendor
Member Since: Sep 2013
Location: Harbor City California
Posts: 2,815
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Hello CF forum,
i realize that this is a dead horse issue that has been beaten over and over again but I’m going to go ahead with it anyways. A read through enough posts on this topic im sure will leave most potential buyers confused as there seems to be a some difference of opinion. On one hand you have the usual horror stories, on the other you have the people who are saying they have 75k miles with no issue. I must admit myself I was a non believer, I bought my car with 12k miles on it and there was no noticeable engine noise or anything that seemed amiss. I was on the fence about even having my heads inspected but thanks to corvette forum I decided to go ahead and wow am I glad I did. Many of my valves exceeded the service limit for play by over 300% I went ahead and ordered the stage 4 heads from AHP and had a local shop install them. I must say AHP is a class act outfit, a pleasure to deal with and now my LS7 is running like a dream, it’s nice to take the car to redline without that looming fear of a potential valve drop. Below I will be posting videos of the play on my stock heads. My goal with this post is just to shed some more light on the topic for potential buyers, or current owners who’s cars are running “fine” I will say again that there was nothing to indicate issues with my motor before hand. I knew about the LS7 head issue but didn’t think it was as wide spread as the internet makes it out to be. Either I am just extremely unlucky, or it is definitely as bad as the hype leads to believe.
Kurtis
i realize that this is a dead horse issue that has been beaten over and over again but I’m going to go ahead with it anyways. A read through enough posts on this topic im sure will leave most potential buyers confused as there seems to be a some difference of opinion. On one hand you have the usual horror stories, on the other you have the people who are saying they have 75k miles with no issue. I must admit myself I was a non believer, I bought my car with 12k miles on it and there was no noticeable engine noise or anything that seemed amiss. I was on the fence about even having my heads inspected but thanks to corvette forum I decided to go ahead and wow am I glad I did. Many of my valves exceeded the service limit for play by over 300% I went ahead and ordered the stage 4 heads from AHP and had a local shop install them. I must say AHP is a class act outfit, a pleasure to deal with and now my LS7 is running like a dream, it’s nice to take the car to redline without that looming fear of a potential valve drop. Below I will be posting videos of the play on my stock heads. My goal with this post is just to shed some more light on the topic for potential buyers, or current owners who’s cars are running “fine” I will say again that there was nothing to indicate issues with my motor before hand. I knew about the LS7 head issue but didn’t think it was as wide spread as the internet makes it out to be. Either I am just extremely unlucky, or it is definitely as bad as the hype leads to believe.
Kurtis
Great Write up and feedback! It was a pleasure doing business with you.
If you ever need anything feel free to give us a call
310-326-2399
or shoot me and email
HP@americanheritageperformance.com
Enjoy driving your Z06 the way it was meant to be driven!!!
If anyone else needs a set of Top Tier LS7 heads we have them in Stock or can rework yours!!! Oh we also do installs here in House!
https://www.americanheritageperformance.com/
Last edited by American Heritage; 06-16-2019 at 10:52 PM.
06-18-2019, 10:48 AM
#13
thanks for this post. I am exactly the person you mention, considering the car but confused by the subject.
can you or AHP talk cost and materials of the heads you bought? certainly will help to know what to plan for.
what else did you do or should you do when changing the heads? did you tune the car or anything like that?
can you or AHP talk cost and materials of the heads you bought? certainly will help to know what to plan for.
what else did you do or should you do when changing the heads? did you tune the car or anything like that?
06-18-2019, 11:24 AM
#14
Race Director
LS7 heads have an alleged issue w/ guides prematurely wearing breaking a valve. Broke valve = new LS7.
Rebuilt heads enhance longevity; however, heads still should be inspected periodically. 10-15 years?
can you or AHP talk cost and materials of the heads you bought? certainly will help to know what to plan for.
Big one's is a shop doing labor or DIY? Fair amount of labor adds to rebuilt heads.
Just heads ~$2,500 at a shop includes rebuild and labor, some more some less.
Email AHP (or whoever you choose) explaining your thoughts/budget.
Pricing on various packages will be provided, each package contains something different & costs accordingly.
Choose one fitting your needs.
what else did you do or should you do when changing the heads? did you tune the car or anything like that?
Most elect doing a cam since motor's apart anyway saving labor $ long term.
I did a cam when heads were rebuilt, no headers/CAI & needed a tune.
If headers/CAI are ever added, another updated tune would be required.
Lastly most want to know what HP their H/C/I LS7 makes, so add p/hr dyno time cost.
Guessing ~$125-$150 p/hr for dyno time, depending on shop/location.
06-18-2019, 11:59 AM
#15
Le Mans Master
When I rebuilt my '08 Z06, I made sure to use the bronze guides, PSI Beehive Springs, and had the Ferrea hollow-stem exhaust valves put in it. Those are a forged one-piece design. Car has been through two new owners now without any issues and is tracked regularly like I should have been doing before I sold it.
I'll be sure to keep a close eye on my LS9 engine. It only has about 12,500 miles on it at the moment, though. I do hear ticking, but I am pretty sure that's just because of the headers. I'll send the heads to Katech at some point for peace of mind.
I'll be sure to keep a close eye on my LS9 engine. It only has about 12,500 miles on it at the moment, though. I do hear ticking, but I am pretty sure that's just because of the headers. I'll send the heads to Katech at some point for peace of mind.
06-18-2019, 04:41 PM
#16
Supporting Vendor
Member Since: Sep 2013
Location: Harbor City California
Posts: 2,815
Received 1,012 Likes
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533 Posts
thanks for this post. I am exactly the person you mention, considering the car but confused by the subject.
can you or AHP talk cost and materials of the heads you bought? certainly will help to know what to plan for.
what else did you do or should you do when changing the heads? did you tune the car or anything like that?
can you or AHP talk cost and materials of the heads you bought? certainly will help to know what to plan for.
what else did you do or should you do when changing the heads? did you tune the car or anything like that?
or shoot us an email
HP@americanheritageperformance.com
We would be happy to go over everything with you.
Also we have our heads and option along with pricing on our website in case you were curious:
https://www.americanheritageperforma...cylinder-heads
https://www.americanheritageperformance.com
06-21-2019, 04:11 AM
#17
Burning Brakes
My first LS7 ('06) went down with only ~25k on it.
My current LS7 ('11) had just over 40k when I bought it. I had the heads pulled, and all but a couple of the guides were well out of spec. I chose to spend the $ for the moldstar 90 guides. Hopefully it's a good "cheap insurance" policy
.
Regardless, by my math, that's 2 for 2 LS7's (of mine), that had bad guides. Losing an engine and my car for ~6 weeks while it was fixed was enough for me, hence, proactively fixing the guides before the engine went "boom".
My current LS7 ('11) had just over 40k when I bought it. I had the heads pulled, and all but a couple of the guides were well out of spec. I chose to spend the $ for the moldstar 90 guides. Hopefully it's a good "cheap insurance" policy
.Regardless, by my math, that's 2 for 2 LS7's (of mine), that had bad guides. Losing an engine and my car for ~6 weeks while it was fixed was enough for me, hence, proactively fixing the guides before the engine went "boom".