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So i sold my 2007 corvette C6 im looking to hop into a 2008 Z06 with only 12,500KM
I've heard LS7 has Head issues any thoughts or recommendations?
how is the maintenance and any other issues i would be looking at
Google it to find thousands of tech articles regarding faulty valve guide issue. Don’t purchase without proof of head fix. Or, have it inspected. A dropped valve = 14K for new motor plus labor.
LS7's 'head issue' lies w/ prematurely wearing valve guides.
Results w/ broken valve(s) dropping into motor. Game over.
However not every LS7 has fragged.
My '08 made it 60K before heads were rebuilt as a proactive measure since the plan's to keep it forever.
Brake discs/pads aren't unusually expensive unless using aftermarket offerings...Z07's the exception.
Good tires like Michelin RFs 4 corners ~$2K + alignment, much less w/ non-RF, brand.
For DIY wrenching maint can be very reasonable.
If at the mercy of a dealer, like me, bend over.
Some LS7 engines have had valve guide/valve failures which will grenade the motor.....question is, How many? If you read this forum with any regularity it seems that every LS7 has this problem which I am sure is not the case. Who posts about how reliable their engine is? I would like to know the percentage of failures that is actually the truth, probably never know. I guess that if you want to sleep good at night, have this issue looked at on your new car if it hasn't been addressed already
Like you I just recently had to make that decision. There’s no way I could have myself accept a base model or a grand sport despite the risk. I just added the warranty to cover myself. Still yet I may do the fix. $3000 on this type of car is worth the piece of mind & well worth it.
I bought my 427 new, have changed the oil every 5,000 miles or year whichever comes first, I send the oil to be tested each oil change. I now have 11,000 miles on the car and each sample tested has come back good. If the heads are going to fail I think it will show up with something in the oil.
From: Central PA. - - My AR15 identifies as a muzzleloader
I believe in the Beer Fairy
Originally Posted by danl23188
I bought my 427 new, have changed the oil every 5,000 miles or year whichever comes first, I send the oil to be tested each oil change. I now have 11,000 miles on the car and each sample tested has come back good. If the heads are going to fail I think it will show up with something in the oil.
I seriously doubt the valve guide problem will show itself in an oil test. The rod issue? Yes. But valve guides? I don't think so.
I bought my 427 new, have changed the oil every 5,000 miles or year whichever comes first, I send the oil to be tested each oil change. I now have 11,000 miles on the car and each sample tested has come back good. If the heads are going to fail I think it will show up with something in the oil.
I also agree that an oil analysis probably won't show any indication of premature valve guide wear. You need to have the heads checked to see if they are within tolerance. Only way to tell.
If I were to purchase ANY car that had an LS7 (427 GS, Z06, Camaro SS), I would have the heads "fixed" immediately. Why risk destroying your engine?
It's a question of risk. There are more LSU out there at 60k+ without valve jobs that are running fine than cars that have failed. It's also a high severity issue.
It's also vastly overblown as an issue. This is a rare issue unlike IMS bearings failing on porsches. Theres a variety of tests to check if its started too.
Heres how I would put it, if you would invest in bitcoins or Tesla, an LSU is a safe bet for you.
About 3% of the LS7's were affected by this issue, so if you play, the odds are in your favor that everything will be fine.... I used to be in the service contract business, & personally wouldn't spend that kind of $$ on a service agreement. My rule was always if the contract was less than the sales tax, then maybe it's worth it...
I also agree that an oil analysis probably won't show any indication of premature valve guide wear. You need to have the heads checked to see if they are within tolerance. Only way to tell.
If I were to purchase ANY car that had an LS7 (427 GS, Z06, Camaro SS), I would have the heads "fixed" immediately. Why risk destroying your engine?
Just curious. I'm a mechanical engineer, so I'm interested in the oil testing. I'm not questioning your statement about the valve guides, just asking.
Why wouldn't the aluminum-bronze/copper or whatever the valve guides are made of not some up in the oil analysis? Or is it less a valve guide wear issue and more a valve guide position issue?
From: Central PA. - - My AR15 identifies as a muzzleloader
I believe in the Beer Fairy
Originally Posted by Jaydubgt
Just curious. I'm a mechanical engineer, so I'm interested in the oil testing. I'm not questioning your statement about the valve guides, just asking.
Why wouldn't the aluminum-bronze/copper or whatever the valve guides are made of not some up in the oil analysis? Or is it less a valve guide wear issue and more a valve guide position issue?
Since I was the one who first mentioned that, I'll take a stab at it. I'm thinking the majority of wear metal would end up in the induction system -> combustion chamber -> exhaust. Not into the oiling system. Or if it did end up in the oil, it would be insignificant vs other sources of wear in the engine. Or it would look like such a small amount it would get brushed aside as possible cam lobe wear, or some other unrelated item. Also, the sum total of metal we're talking about being missing is almost insignificant as oil analysis goes. So, considering it's such a small wear item, and such a small % ending up in the oil, I wouldn't count on it being found.
Not that it really matters, the root issue on the affected heads is that the centers for the valve stems and the valve seats were not machined perfectly centered, and machined in separate steps rather than one combined boring/cutting process... not sure of what the actual offsets were found to be, but the valve stems would've had a constant lateral force within the guides that eventually would result in a stem breaking, & then you all know what the result of that would be...
On my 2007 Z06 had rocket arm failure. 1,500 sets were made in China. No operational problem as screens catch the roller bearing that come out after the retainer fails. Replaced with competition quality set - would never replace with GM garbage.
Did my heads as valve failure will destroy the engine. Only a few high quality head rebuilders in the country - be careful.
Disgraceful that GM never did the obvious recalls. That is why I would never ever buy a C8 until it has been out at least two years. Do not trust GM. Even with a warranty. I would of want to deal with them. Replaced with a C7 Z06.
i just bought a 2010 with 85k miles.. valves/heads done last year.. just had a full service done..all fluids done and car looed over.. whats the reliability after the heads and valve guide fix? Im debating a warranty for 2 years but could also use that money on seats which Id really like..hate the c6 seats
i just bought a 2010 with 85k miles.. valves/heads done last year.. just had a full service done..all fluids done and car looed over.. whats the reliability after the heads and valve guide fix? Im debating a warranty for 2 years but could also use that money on seats which Id really like..hate the c6 seats
You should post this question in the Z06 section of the forum. Lots of knowledgable people on this subject since it comes up quite often.
I bought a Z06 last year and had the heads fixed. Doubt oil analysis will help. Few enough failures that I doubt anyone has clear data to show a correlation of impending valve failure to oil analysis data.
Purchasing 2008 Z06 /Head issues?
