Z06_1

As a precautionary measure, I decided to proactively check the guides on my newly acquired C6 Z.

I've only checked the passenger-side head so far, but the results were clear - new heads are in my future, and if I don't act soon, it will be a new motor.

The car has approx. 16,000 easy street miles, never saw a road course or drag strip (previous owner drove it like any other typical daily driver).

I also noticed (and on this point I am not 100% certain, I would have to start logging to track it) that is seems like it used about 1/2 - 3/4 of a quart during the 800 mile (all freeway, motor turning about 1500 RPMs) trip home. This surprised me..

There is NO excess valve train noise, NO visible smoke upon cold start up, exhaust tips / inside as far as one can see are pristine, NO oil in the throttle body.

I am in the process of transferring the exiting GMPP warranty to my name.

So, the questions are as follows (and unless you have first-hand knowledge, please state your response as an opinion - those are welcomed as well).

1. What happens if it blows up BEFORE the transfer has completed? It takes time to sign the form, time to mail it, time for them to process it, etc. Will I still be covered (since it is within the 30 day transfer window)? Will the previous owner have to file the claim? Will it be denied because I am driving it now? Does it matter than we live 800 miles apart?

2. I ASSUME most of us would prefer to run to the dealer and tell them "hey, I need a new set of heads", and save themselves, GM and whomever else the pain and suffering of a complete motor swap.. But is this approach problematic? Is it appreciated, or will I have a harder time with the dealership, and the easy button is to just let it blow? What would you do?

3. I assume that I have MY choice of places to take it to, and I ASSUME they must be a "GM certified" shop.. I do all my own work; I've built several motors, many heads and cam swaps, R&R diffs and transmissions, etc. No one but me ever turns a wrench on any car I've ever owned - and now I am faced with this situation.. The prefect scenario would be for me to pull the heads and they hand me new ones - good luck on that dream. The second one would be to pick a well-known, trusted performance shop - again, I assume that is a pipe-dream. I guess the third (and probable) scenario is I hunt around for the best GM tech / shop I can get to within reasonable distance, that will take some pride and care in the job. Input??

4. I don't really have a complete set of service records.. The previous owner never had to take it in for anything. The ONLY modification is a Mild-to-Wild switch, and I assume that is not an issue (if it is I will pull it off the car tonight). The oil was changed at approximately 20% of remaining life (I know, I know), so it was probably changed 3 (or 4 at the most) times during its life. For folks that have had their defective heads replaced, what sort of scrutiny are you put under for maintenance records and modifications?

5. I realize the dealership isn't going to simply take my word about the issue - so do I have to pay something up-front to force them to check the heads? Has anyone ever only had one head replaced? On the contract, it says "zero deductible" - so does that mean they will not charge me for the diagnostic or will charge me and I will be reimbursed?

Finally, a comment - this whole thing sucks.. I was in the camp of the "relax, it really is only a small percentage of cars" for so long, but now I am becoming more convinced that it is more a function of the typical Corvette owner driving patterns, that put so few miles over so many years that the issue never surfaces (or takes a really long time to surface). In other words, I think there are MANY more LS7 on the road right now that haven't failed due to low mileage, but will eventually if given the opportunity, and darn it, that just sucks..

THANK YOU IN ADVANCE! I really need to get my ducks in a row quickly on all of this!

ctsv510

If you have measured the guides to be bad and you have a warranty, take it in and complain about valve train noise and oil consumption and ask for the valve guides to be measured because you think they're bad. They may tell you that you will have to pay for the labor if they discover that the guides are in spec and warranty doesn't cover the work, but if you know for a fact they are outside of the service tolerance then you won't be charged.

What year is you car?

flyby763

I just transferred a GMPP to my car back in May when I bought it. Takes about 3 weeks to get the paperwork once the transfer form and check are received. My plan is to not even worry about it until it blows and if it doesn't replace the heads before it expires.

Mark2009

I would stay away from GM and their dealers and have the heads replaced/rebuilt either yourself or by a trusted independent shop. There is zero evidence that new GM heads will last any longer than the heads you currently have on the car. Not there is not a ton of evidence that rebuilt or aftermarket replacement heads will fare any better, but there is sufficient evidence and logical reasoning to make a reasonable presumption that they will last longer than new GM heads (presumption of more accurate machine work, for starters).

The only way I would deviate from that is if you were within reach of one of the few top notch GM dealers in the country, like Abel Chevy in Central California, and then I would want the new GM heads sent out to a machine shop to be checked for proper clearances and alignment before they were installed on the car. Otherwise I wouldn't trust the average dealer to swap the heads even if I knew for certain that the new heads were good.

I wouldn't sweat the oil consumption at this point; these cars are notoriously picky in getting a good, consistent oil level reading (dependent upon oil temperature as well as 'settling' time). If the combustion chambers and pistons look good once the heads come off then you should not have any oil consumption issue going forward.

Once you get the GMPP transferred into your name you can cash it in to offset the cost of having the heads rebuilt/replaced.

Z06_1

2011.

71corvette

Well, this won't make you feel any better but I just test drove from a Corvette dealer a '09 Z06 for three days. It had 16k on it and there was no doubt in my mind that it had a valve issue. At 1600 rpm and higher, it sounded just like a lifter and the noise was at the speed of a lifter but we know it is valve guide wear. GM has already shown that they wouldn't admit to defects in millions of their cars and trucks so why should we believe that only very few Z06's have this issue? The other thing that is interesting is how they scare you into thinking that any aftermarket part will void the warranty. This is just not true unless they somehow rewrote the Magnuson Moss act. I worked for an OEM for 28 years and unless you had scientific data that proved the aftermarket part caused the issue, the courts never ruled in favor of the OEM. I realize this post is a little off base from the questions posed so forgive me for that. If you checked the valve guides and have the data that they are way out of spec, I'd take it in and trust they will find the same thing. They won't be able to charge you because you will make them prove to you that there isn't anything wrong. You sound a lot like me in that no one puts a wrench to my cars because I am a Master ASE with a ton of experience. But sometimes you just gotta trust that the dealer will do what is right. Actually, the dealer wants to fix your vehicle, it is the fear of the OEM not paying the warranty claim is what causes the issues.

JeffInDFW

With your 2011, you still have the good main bearings made with lead. I would try to hang onto that motor. If you let it blow, I wonder if you might get a replacement engine with the 2012 and newer bearings that are lead free due to Europe regulations, and have shown a tendency to show why they put lead in the bearings in the first place. They fail.

Les

I wouldn't drive the car until you have written confirmation in your possession of your GMPP policy coverage. There's no sense giving them a chance to find a loophole and deny you coverage if something lets go. Try to find a quality dealership to handle your warranty claim- somebody who has experience with diagnosing LS7 excessive valve guide clearance and understands the process. If they deny knowledge of the valve guide problem, stay away and try another dealership. They'll need to do their own measurements and will charge you for their labor if clearances check out within tolerances. If you're confident of your own findings, this will not be a problem for you. Their protocol specifically mentions that they are to check for tolerances if the customer complains of valvetrain noise- I'm sure it's there if you listen closely, right?

I realize good service depts. are hard to find but they do exist. Ask local Vette clubs or put the request out in this forum in your local section. There's no way I'd cash in the GMPP policy until you know exactly what condition your engine is in, especially if it extends for a decent time into the future. The oil usage might be related to guide wear but mine were well out of spec and I've never had any oil consumption. I'd want to make sure there's not something else going on with that. GM is giving complete new heads now to replace the bad ones and your whole engine will still be covered, not just the heads. PM me if you if you need any more info, and good luck.

American Heritage

We have replaced LS7 heads in our shop via GMPP and other aftermarket warranty company's. Some Shops accept aftermarket warranty's including gmpp.
With that said often times warranty company's don't want to replace anything except the failed part. For example we have had GMPP just pay for the replacement of the guides (parts and labor). They refused to pay for new exhaust valves or to treat the intake's. They said they were ok with "upgrades" but they would be out of the customers pocket.
You didnt say where your located. If your in California we would be glad to help you out.
http://www.americanheritageperformance.com/
310-326-2399

Z06_1

Hey guys, please keep the replies coming! I hope to have enough information to formulate my plan by Monday.

Still interested to hear more about the warranty claim process (service record reviews if any, paperwork loop-holes, gotchas or pitfalls to avoid), how long they typically take to do the work (can they check the measurements, then I take the car back while they order new heads, etc.).

A.H., I am sending you a PM now.

GMuffley

Where are you located?

Garibaldi

1) Check with GM to see if your warranty is already in effect

2) I have had an independent shop do warranty repairs on my previous Vette when it needed new rings. GMPP paid, but I called GMPP to make sure that was the case.

GP

Z06_1

Atlanta.

Painrace

Call MTI at 770-919-7774. They will take care of you. It may cost you a few bucks but the heads will be right.

Jim

Z06_1

Reese was on my list if phone calls to make Monday AM.. Are you saying just deal with it on my own or that GMPP will pay them to do the work?

ATC399

So what did you use to test the valves?

Bill Dearborn

The dealer you want to take it to can see if the GMPP is in effect. If you don't want to do that call GMPP NOT GM. Two different companies. http://www.gmppdirectsmith.com/ .

I can tell you this if the dealership doesn't find anything wrong with the valves you will have to pay for their work. GMPP doesn't cover diagnostics unless a repair follows.

If something is found wrong then the repair will be done based on the contract you have with GMPP. If its a no deductible Major Guard plan you get a dealer work order with no charges on it.

They are usually very easy to work with. A lot of times coverage is confirmed or denied based on the labor code the dealer service adviser enters into the GMPP computer. If the computer denies the claim the service writer will tell you. If that happens call GMPP and make your case to a person. Two years ago when the O Ring around the tube in my oil reservoir slipped and the tube started making loud noises in the cabin GMPP denied the claim due to the labor code identified to repair the problem. They don't normall cover things like O Rings but when I explained this O Ring was inside a tank that supplied the engine oil and it was rattling and maybe causing metal chips to get in the oil I asked if it would be cheaper to pony up the $400 for the repair of $15K for a new engine. The guy went approved the repair right then. The next day I went to the dealer and they called GMPP to verify the repair had been approved and then went ahead with the repair. Very easy ot handle.

Bill

Z06_1

I pulled 5 rockers in total on the passenger's side (will probably check drivers side in the next few days), looked at the wear pattern on the top of the valve and face of rocker (looked like carp), then, with the spring on attempted to move the retainer / tip of the valve in East-West and North- South directions.

The first two exhaust valves I checked, I wasn't completely sure about.. There was slightly more movement NS than EW..

But when I got to the first intake I checked, I felt a little sick to my stomach.. The NS movement is about 4 times that of the EW, and you don't need a dial indicator (I own one, but trust me, it is a waste of time to set it up) to know it could snap the head off the valve from fatigue at any moment.

So, to the point, do I know exactly how far they are out? No. But when you have so much movement that it is easily detectable with the naked eye; out of spec a little is still out of spec..

Z06_1

Good point about the bearings!

Z06_1

I called around, and ironically, the fact I still have the factory warranty in-tact is preventing me from utilizing the one certified tech in my area (he moved on from the dealership and works for a private shop).

So effectively my "problem" is although I can get the heads replaced for free, I dont have anyone I can take it to that I trust.. I may end up calling Hendricks and see what they say / recommend..

Anyone have a recommendation anywhere in the Atlanta area, please let me know (David Fultcher says there aren't any..).