Runs11s

I saw a red C7 on I-75 northbound just north of Lima Sunday afternoon. It looked awesome.

DesertDog

Hi All. I just read the sticky on this issue and the GM Response says that it is a VERY small number of engines with this issue: The peak total was 6.5 bad engines per 1,000 engines produced. That is less than 1%.

They also said that if it doesn't show up as a problem early in the engine life that the engine will be fine.

I also was considering buying a newer used GS (2011 or 2012) VS. a 2009 or 2010 Z06. I will simply look for a good, clean Z06 with around 15K to 20K miles on it, pay less than I would for one with fewer miles, and go for it.

The valve guide issue is a problem with a very small number of engines. This is NOT the end of the world!

Over and out,

Desert Dog

WhiteKnight

I don't think the valve issues have been blown out of proportion but the cost to be proactive and fix the problem up front is minimal on a used C6 Z06. I recently bought an '08 Z06 and the first thing I had done was WCCH heads, cam upgrade and exhaust. Cheap insurance if you ask me. Even after all of that it's a lot of bang for the buck. This is my 4th vette and this is by far the best yet. It will only get better with the C7 but a new loaded C7 will be pushing 75-80k similar to a new C6 Z06. At 40-50k an '08 or '09 Z06 is still a bargain IMO. What a fantastic car! I say go for it and don't look back.

ibleedgreen

Ah, but so many don't get this. Remember, you can't put anything on the internet that's not true...

LFZ

Do you still leave milk and cookies for Santa Clause.....?

DesertDog

Well.....no....I've discovered that Santa likes a large Johnny Walker Black Label with a splash of soda.

But seriously folks! If the GM data in the sticky is correct....and I trust the Moderator is not making this stuff up.....then this is an issue, but one that only a small percentage of folks will experience.

In addition, those that experience it will do so early on during ownership so they will be covered via the warranty. If you make major mods, you lose out, of course.

This tells me that people buying a used Z06 with, say, 20K miles on it are probably just fine.

Again....this is based on the data provided by GM through their analysis of Z06 engines with this issue. If this data is wrong, then someone needs to show the "real" numbers.

What I think is going on here is that this has been blown out of proportion due to the fact that people accessing this forum are a very dedicated bunch of car guys and gals but represent a very small percentage of total Z06 owners.

Just my 2 cents.

Desert Dog

Gary '09 C6

DD, I think you're being optimistic to rely on GM's statement as "the last word" on the matter. There are quite a few reports
here on the CF of LS7 engines built either before 2008, or after the February 2011 date, that have had partial or complete failures.

Many here, including me, believe that GM is simply trying to financially manage the "LS7 problem" and limit their cost-exposure
to unmodified LS7s that remain-in-warranty.

But, it can also be gleaned from all the CF reading that a basic valve-train/heads fix should only cost about $2K--$3K,
so factor that into your total costs and you should be fine. Knowing the latter, it's more about the inconvenience
and aggravation factor, primarily.

[IMO]

ByByBMW

Having owned a Z06, and spending way to much time on the Z06 forum, I can pretty much tell that most of you who are naysaying the valve train issues on the LS7 haven't spent much time over there.

The GM statement has been pretty much negated by all the negative occurrences of LS7 engines blowing. While DesertDog makes some good points, there are other statements, his and other posters, that have me chuckling.

I wouldn't buy another Z06 unless it had the heads reworked by a respected aftermarket shop. Period. But that is only one person's opinion, mine.

For folks thinking about a Z06, they are wonderful cars, truly the poor mans supercar. But DO YOUR OWN HOMEWORK!!!!!!!!!! Don't rely on other posters opinions, including my own. Spend time on the Z06 forum then decide.

You have been advised.

Runs11s

Good post and good advice.

DesertDog

I just looked at the total Z06 production numbers..(2006 to 2013). The total comes to 27,996.

Now, if the GM defect stats are correct, then we are looking at under 300 Z06's with this problem.

Only 300 maximum. I know many of you will flame me and say that number is crazy....but I am not necessarily endorsing it. I'm just pointing out that it's the only data I have seen.

I have no idea how many folks on this forum have posted about having this problem, but it seems to me to be well under 300. Maybe 35 or 40? Does anyone have a real handle on the quantity?

I guess my point is that I haven't seen any statistical analysis done on the actual numbers of failures reported on this forum....(and I apologize if it exists...please point me to the data).

All I have read is "lots of people" and "many", etc..

But 300 defects, even if major, out of 28K total is not that huge, and most would have been covered by the warranty.

Bottom line: Until I see some data that shows me that the chances of me purchasing a used Z06 with this problem is well above 1%, then I will not be deterred from my quest for a good used 2009 or 2010 Z06.

Desert Dog

Runs11s

Now THAT is a great post. Hard to dispute the numbers!

clogan

Well, all I can say is my 2006 had crap heads, and I didn't learn about it until it had 38,000 miles. By then it was out of warranty by time (36 months on a 2006), and GM told me there was nothing they could/would do. I'm betting the defective heads can be found in virtually all LS7 engines. Some are just luckier than others as to when the symptoms present themselves. You roll the dice if you want. I had my heads replaced, and will forever remember the crap heads that GM refused to stand behind. If I backed my work like GM, I'd be out of business. Come to think of it, GM actually DID go bankrupt, didn't they!!! Wonder why!!! Not surprising with their lack of committment to quality.

DesertDog

Good point! And I am not trying to defend GM here at all......I am simply trying to get to the "real" data. I had a Tahoe that blew it's transmission (thankfully under warranty) and they did replace it. I was luckier than you were, I guess.

There may very well be some defects in most LS7's, but we don't know the details on the total number, or causes.....at least I haven't seen the data. If someone has it please send a link! I think it would be very helpful.

71Pantera

I have an 08 with 30k on it and love it and drive it like is made to be driven. Guess I am lucky.

MTPZ06

Are you excluding those owners that had valve guide wear measured to be well out of manufacturer spec and had their heads replaced and/or rebuilt prior to catastrophic engine failure; or would you consider those folks as part of your "actual number of failures"?

Gary '09 C6

both types of defects/failures need to be included, as both are manifestations of the problem that is being
focused on here...the one (excessive valve guide wear) is believed to precede the other (valve breakage).

dstiger

Run ! ! !

DesertDog

Excellent point. I would think that we would have to include BOTH blown engines and those found with wear. In reading what GM sent the moderator it appears that regarding the "small number" of cars that have this issue, they say that they discovered the condition "through our cylinder head warranty data".

I'm going out on a limb here....but I would read that to mean that some folks had the LS7 blow, (obvious problem); and others had "excessive valve train noise" and took it in to be inspected. The dealer then pulled the heads and found the issue.

That is the way I read it. If that is the case, then it covers not just obviously destroyed engines, but those with a propensity to do so.

I could be wrong! But that is the way I read it.

Below is what is on the sticky from GM on this subject:

Desert Dog

Originally Posted by Chevy Cust Svc View Post

Hello all,

LS7 Valve guide issue summary:
• Affects a small, number of '08, 09 ’10 and ’11 Z06’s
• GM discovered the condition through our cylinder head warranty data involving a very small percentage of our vehicles.
• Through inspection of returned heads, it was determined that a machining error in the valve guide had occurred at our head supplier.
• The quality issue has been contained as of Feb 2011 with 100% inspection of all heads.
• The most common customer complaint has been excessive valve train noise.
However if the condition is not addressed, it could result in engine failure. To date, where this condition has been observed, it has occurred early in the vehicle life.
What customers need to know: They should drive and enjoy their vehicles without fear. If their car demonstrates this condition, they are likely to hear unusual valve train noise first. If you have a concern regarding this issue on your personal vehicle feel free to contact me through private message on this forum and we will work to assist in resolving your concern. Feel free to contact me through Socialmedia@gm.com please put attention Evan in the subject. As always, vehicles that have modifications to the powertrain or the calibrations, are no longer covered by GM's warranty.

Sincerely,
Evan, Chevrolet Customer Service

pkincy

Desert Dog, I expect your analysis of the numbers is as good as anything else we have.

As scary as it gets, it only costs $3k to fix. Spend that on an extended warranty or spend that on new heads. Or roll the dice and go with that (I am going to wildly speculate here) that 200 to 1 chance (0.5%) that you will be just fine.

I bought one and love it.

My solution was to leave it stock and use the GMPP warranty as my insurance. You get to pick which of the 3 choices you are most comfortable with.

DesertDog

We are moving to San Diego in September, and I plan to sell my 2011 2SS Camaro as soon as we arrive and start my quest for a good used Z06. If it blows, it blows.....but I plan to keep it stock....and I think the odds hugely favor a good engine over a bad one.

I owned a C-5 and C-6 (both coupes) so it's time to get a Z06 and keep it a long time.

Desert Dog