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GM response to failing LS7 engines

164K views 97 replies 40 participants last post by  TacoSauced 
#1 · (Edited by Moderator)
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 valvetrain 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
 
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#94 ·
Congratulations on your new toy. Post some pics when you get chance.

As for getting your local Chevy dealer to do a valve stem test at no charge don't count on it. You are way past the 36/36.

My personal experience with the LS7 is they seem to tick a bit at low rpm's, and from what I have been told by my technician is that is just an inherent quality of the motor. So don't worry about that.

The LS7 exhaust valve mortality rate is probably greatly exaggerated. I am not saying it doesn't or won't happen, it is just as likely for some other part to fail in a motor that is capable of 7000 rpm's.

I had my heads done, but it wasn't so much that I feared the valve failing, as I wanted to have my heads ported for better efficiency. So new valve springs, new Ferrea solid exhaust valves, new trunion kit, ARP head bolts, etc. I will admit however when I was getting the work done I did tell my wife that the exhaust valve issue was why I was spending $3,500 on my motor. My bad. In the end I picked up another 25-30 hp. and tq. at the flywheel after having the whole thing tuned again. I think most of the people on the forum will tell you don't bother with the heads. As long as you keep the stock camshaft and don't go over .630" of lift you should be fine. If you are going to do some mods like a cam, them you should look into geting the heads redone or replaced with a aftermarket head.
 
#96 · (Edited)
Congratulations on your new toy. Post some pics when you get chance.

As for getting your local Chevy dealer to do a valve stem test at no charge don't count on it. You are way past the 36/36.
Thanks and thanks for the helpful reply.

So I did a quick search last night to see if there've been any developments since the article was first posted (years ago). I saw mention of a Class Action suit filed back in 2015. Wanting to know about what became of that legal action, I Goog'ed some keywords including class action lawsuit just now and see quite a few articles speaking either of the law suit filed in 2015 or one filed in 2017. The article below was published March of this year. Unless the author of news article is speaking of the lawsuit filed in 2017, it suggests we might have three Class Action suits filed.

 
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