mdiers

Does anyone have an idea of what percent of c6 z06's drop valves?

juanvaldez

Does it matter? Will you buy one if it is 1%? 10%

Sy1616

<1% as far as I’m aware.

c5racr1

100 % eventually

juanvaldez

<1% because they are not driven.

UmCanesZ06

I've had 4 Z06's and never had a head/valve issue so my percentage is 0

juanvaldez

I only tore down one LS-7. All intake valve clearances 10 times factory spec.

Dan_the_C5_Man

A much better/ more relevant question is "how many LS7's have valve guides out of spec.?". From the data we've seen just on this forum alone, an overwhelming percentage do.

Out of spec. valve guides are clearly the number one contributing factor to valve failures.

Now, some people on this forum are gamblers, and they continue to drive their cars knowing full well (or in the case of the "head-in-the-sand" crowd, they don't even bother to check) a critical component is worn past its service limit. They are litterally "playing the odds" that they won't get burned.

One can be just lucky, or lucky and smart.

LV Vette

Got a question for all the people saying the valve fix is a waste of time. What percentage of S.W.A.T. officers are shot and killed? What percent of S.W.A.T. officers wear bulletproof vests? I realize this is a harsh analogy, but just get the heads fixed and not have to take the chance you will be one of the unfortunate ones.

_BlueZ06_

How you interpret the information is dependent on the person. There have been a number of LS7s with dropped valves considering the low mileage put on most Z06s. As Dan mentioned, many of us have had ours checked and fixed which reduces the number of actual dropped valves. I'd have them checked and then make your decision if the risk is worth it.

TXGS507

Meh,,, it rarely happens ever, I wouldn't worry about it.. Drive the **** out of that thing!!!

Apocolipse

Did I miss summer and it is back to winter threads??

sam90lx

I once thought the hysteria was over blown, had mine checked on my bone stock 2012 with 17899 miles..... 16 out of 16 we’re out of spec.

h2oskiman

Ok here's my problem. I have an 08 z with 37k on it now. I have an extended warranty for 2 more years. I'll never hit the miles in two years. So do I drive it till the warranty is about up .If I check it now and find problems with the valves will the warranty take care of it before something happens. If I have the heads redone by some after market company there goes my warranty.It is completely stock. Blackstone report was good. Just not sure what to do ?

NotreOkc

Your warranty is not going to cover preventative maintenance, so drive the hell out of it for the next 2 years then decide if you want to address the heads for peace of mind. I never even checked mine on my Z06 in 4 years and never had an issue.

moose.b3

Wrong! If your heads are out of spec your warranty will pay to replace your heads. GMPP has replaced 2 sets of my heads because they were out of spec. The second set is being replaced with AHP reworked heads now, payed for by GMPP. I really can't believe the bad advice that is still being given after all the heads that have been measured out of spec. Let alone all the engines that have holes in their blocks from broken valves.

sam90lx

Same here, GMPP is covering my AHP head replacement as well.

NVNO1

Well my Z06 is in my garage with a destroyed engine as we speak. I'm having AHP build me a new engine as my Z06 was out of warranty. It's an 09 but only has 5k miles on it.

That said I also have a 2015 Z/28. It is still under warranty until June. My question is how do I get American Heritage Performance reworked heads on it? Do I have to take the car to the dealer to have wiggle test done? I so cringe at the thought of having the dealer within 100 feet of my car. Basically how did you go about having AHPs heads on your car using the GM warranty?

moose.b3

I took my Z to a Chevy dealer that is very familiar with the valve guide problem. I had them do the wiggle test to give me an indication of whether or not the valves seemed to be out of spec. If the valves seemed to be in spec, I was going to have to pay for the wiggle test. But both times I had the test done, the valves were deemed to be out of spec. The first time was 5 years ago and the heads were replaced with new GM heads that lasted 23,000 miles. A lot has been learned in the last 5 years and GMPP now works with AHP so we can get their fixed heads. You're not that far from AHP, call them.

NotreOkc

Then I stand corrected on the GMPP warranty. I know several buddies with Z06's that were not covered. So it is not completely bad advice.
All the engines that have holes in the blocks? All ~1% of them?