roadandtrack

** Update in post # 34 **

My situation...

2010 Z06 with 7500 miles. 100% stock and never abused.

My helpful local dealer did the wiggle test and found 0.030" on one valve and 0.006" on another. The 0.030" was so bad that they didn't need to dig any deeper! This valve guide wear issue is real!

My question is will the new warranty replacement heads be 'fixed' or is there a good chance I will have the same problem 7500 miles from now?

rockinSeat

Heh, I think I started a thread with the exact same title a year ago. You know what they told me? No one knows. Those measurements put another tally mark in the "machining error" camp to me. I mean, a .03 at only 7500 miles? I wonder if it was cut wrong right from the start? Heh, drive another 10k, have the same guys do a wiggle test, and let us know.

I have 3k miles on my new heads. My advice is to extend your warranty and monitor the guide situation.

2k Cobra

In my book, it's a Crap Shoot. Who knows.. Some here have suggested going through this every 10K miles. I elected not to do this.

I had mine replaced as well and got rid of the car.

Mark2009

Nobody knows.

The ideal situation would be to have a competent, experienced machinist disassemble and check the new heads before they are installed on the car. Of course, if dealing with a GM dealer that will likely not be possible.

It might be helpful to others if you mention the dealer's name or location -- many GM dealers refuse to do the wiggle test.

At least you know where to go in 7500 miles to have it retested.

NHRA95

Any increase in valve train noise?

Matt Cyber Z06

Anyone:

Have dealer replace heads and still come up with a Problem later through inspection
or failures ?

Turbo2L

You are soon to find out your dealer technician friend has a lot to learn. This has been thoroughly documented here and across other liar forums.

GMuffley

I had my heads done at a dealer; the tech (a very well known Corvette specialist) recommended not using the stock valves and guides on the rebuild. My car was more than 5 years old when I had the wiggle test done, so the repair was not done under warranty.

Matt Cyber Z06

Im sorry, but I don't Understand anything you typed ?
maybe your trying to be Smart or your stating your opinion, either way I don't understand.

3LZZ06

I thought it was just me. His post makes absolutely no sense.

OH THREE Z

According to GM, the issue was contained in early 2011. I'm not sure if I believe that or not. There have been a very small amount of late 2011,2012 & 2013 LS7 failures documented. The failures that I'm aware of were not valve related (spun bearing, broken spring ect) This can either be attributed to the problem actually being fixed or too small of sample size and too few miles on those Engines to have use able data. I for one have a 2012 Z06 with 10200 miles... no issues, but I have not had the valves checked yet. Good luck!

Matt Cyber Z06

My tech said All the part numbers are the same since 06

OH THREE Z

It was a supplier machining issue per GM, not a raw part problem.

Matt Cyber Z06

While that does make me feel better (dealer just replaced my Heads with complete new one's through-out)

Again, that is GM's claim.....

Dirty Howie

Thats just pathetic


DH

Mdm23

My gut feeling is that all the LS7 heads from 06-13 are exactly the same. So even replacements will have potential to give you problems down the road. I still can't believe how GM handled this whole situation.

OH THREE Z

Until we see (hope that we don't) LS7's dropping valves built after early 2011 or earlier cars with replacement heads failing again I will try to accept that the issue has been contained. I can't completely fault GM due to the fact that we simply do not know the percentage of failed LS7's out there. My guess is around 5% and if that's close then IMO it's something that is easier for GM to just deal with through warranty claims. From what I have seen/read, It does seem that they have been more than fair with the unfortunate owners of blown engines.

Let's hope the LT4 doesn't have the same stigma.

chetly

Wonder if we'll see the same situation with the new Z/28 being they have the LS7.

Mark ZR1

^^^^^
Can't imagine GM wouldn't have made corrections to the heads before promoting the Z/28 ???

Wndotintman

I have a friend that has a 08 that had engine replaced on 4/12 due to a dropped valve at 21K miles.

We checked his guides a few weeks ago and one head is ok and the other the intakes were almost double the service limit. All the exhaust were great. The replaced engine had 10K miles on it.

I dont think any years are safe from this issue. I have a 09 with 14K miles on it and it checked good. If I keep the car long enough, Ill check it again in 10K miles.