Wass

I have a 09 Z06 with a warranty that ends mid June. I'd like to find a dealership knowledgeable about the valve guide clearance issue concerning some LS7 engines (2006-2011). Prefer someone who has performed this test on the Z06. My local dealerships are clueless. Central PA would be great.

Originally Posted by Chevy Cust Svc

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.

Frans96ss

In my opinion there isnt much point in getting the "wiggle" test done... Just get the valves fixed and never worry about it again.

Wass

If a Chevy dealer determines my guides are out of spec., I can get new heads at no cost. Why shouldn't I attempt this route first? I would trust new heads from GM.

If I didn't have a warranty remaining, I'd have the heads rebuilt with stock valves and springs, PM guides preferred but bronze would be acceptable. I am not interested in SS valves and dual springs. Thanks for any advice on this subject.

Frans96ss

I havent seen a dealer cover new heads yet... If they have i would be shocked.

Wass

I have read a few reports on the Z06 forum of dealers replacing heads under warranty. And in some cases, entire engines after the valve head broke off. Here are a few warranty replacements.

http://forums.corvetteforum.com/1585970654-post62.html
http://forums.corvetteforum.com/1585990986-post63.html
http://forums.corvetteforum.com/1585995951-post66.html
http://forums.corvetteforum.com/1585744227-post18.html

DRM500RUBYZR-1

Do you actually have "excessive valve train noise"?

If yes, insist any dealer investigate it, and if they do not know how refer them to the service bulletin, or reach out to the manufacturer for assistance in the referral..

If not, stop worrying and enjoy the car. Taking it to a dealer for anything, even a test, just invites trouble where none was before.

If catastrophic engine failure caused by wobbly valves was about to occur, it would seem quite logical that the symptom of excessive noise would present itself long before the failure.

I HAD AN O3 50th with occasional piston slap that sounded like it would soon explode and it had 1900 miles. Soon realized they all do it, and stopped worrying. Used the proper oil and kept it perfect, and the sound faded away. Very glad I did not let some potential goon start screwing around with it and creating real problems

So if noise is prompting your concern, then pursue with vigor.
If expiring warranty is the cause of your concern, better make those valves awfully noisy before your dealer visit, and move fast and pray hard.

Marty
NCRSZR1
95PACER

DOUG @ ECS

Hey John, if you would like us to take a look at it for you so you have something in writing to go to the dealer with as "conformation" just let us know. It doesn't take too long to check.

Hope your enjoying it!

Wass

Marty,

I've read too many reports here of out of spec valves without excessive valve train noise. I realize that is supposed to be a symptom of the problem, but apparently it's not always the case. However...I would tell the service rep the valve train noise has been on the increase. Thanks.

Wass

Hi Doug,

You must be reading my mind! I've told a few friends recently that I'd probably end up taking it to your shop. The odds of finding a Chevy dealer knowledgeable on the subject are quite low. Thanks.

0HorsePowerAddicts

We have had a Z06 come to use for a wiggle test that was still stock. We found it was out of spec and the next day the owner took it to the dealer with the measurements and the dealer ended up putting new heads on the car for the owner. So it is possible.

If you decide on rebuilding the heads give us a call. We always have a few C6Z's here getting our built heads on them.

Wass

^ Thanks for that information.

CTYANK2

Let us know how this works out for you.

Wass

ECS squeezed me in for next month. They are very busy.

flange

you might give bryner chevy a call in Jenkintown(near philly). they fixed some stuff for me that another dealer couldn't in three tries.

Glennm27

I had a misfire on my 08 LS7 at the 4th cylinder that would not go away. My dealer checked it out. As it ended up, the LS7 had worn valve guides. They replaced both heads and the cam under my GMPP extended warranty at $0 cost to me.
So for those that think GM dealers won't do this, you're mistaken.

Wass

Glenn...What is the name of the Chevy dealer?

Ikester

You are smart for addressing this now before the warranty expires. My friend had an 08 Z06 here in north Jersey and the motor let go when he was just cruising at 70 on 6th gear. He had documentation of dealer visits for excessive oil consumption of which the dealer said this is normal.

The warranty had already expired 1 month prior to the incident. The dealer would not warranty anything and it was the valve guides that were the root cause the engine failure.

Glennm27

Your friend should contact GM. Go above the dealers head. GM WILL cover at least part of his repair. It's a known problem with specific year LS7's and GM is very aware and WILL help owners of cars out of warranty.