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Good to hear everything worked out for you. Not to shabby hp numbers (now save up for rear tires! :lol:)
Seriously! I'm trying not to blaze my brand new Michelle Pilot ZPs! Good thing these tires hook up better than the GY's, still have to watch 1st and 2nd though.
 

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Seriously! I'm trying not to blaze my brand new Michelle Pilot ZPs! Good thing these tires hook up better than the GY's, still have to watch 1st and 2nd though.
Why no cam? :(.
 

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Why no cam? :(.
I probably should have but couldn't justify the extra $2k at this time. I dont race the car and wanted to keep factory like street manners... plus I didnt want to give the smog shop somthing to gripe about. Even though a cam wouldn't affect the visual, with my luck they would find some language to fail me based on sound...lol.
 

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I probably should have but couldn't justify the extra $2k at this time. I dont race the car and wanted to keep factory like street manners... plus I didnt want to give the smog shop somthing to gripe about. Even though a cam wouldn't affect the visual, with my luck they would find some language to fail me based on sound...lol.
I'm sure I will kick myself a couple years down the road tho....:cheers:
 

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GM is a little late....5 or 6 years...and a little short on their responsibility. Their dealings with the Z06 valve issue cost them a new truck for me and a new car for my wife.
Mine is fixed without their BS help. I'm sure I will not be dealing with GM quality again.....just someone else's sorry quality.
 

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GM is a little late....5 or 6 years...and a little short on their responsibility. Their dealings with the Z06 valve issue cost them a new truck for me and a new car for my wife.
Mine is fixed without their BS help. I'm sure I will not be dealing with GM quality again.....just someone else's sorry quality.


I noticed this in another thread...

Posted By lebvette
Re: How Much Horsepower are you making?

551/501 Stage 4 Stalker from Ragin Racin and the goodies that go good with it.
I see you've done some aftermarket engine work on your Z. Did you have valve issues yourself?

Mike
 

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I noticed this in another thread...



I see you've done some aftermarket engine work on your Z. Did you have valve issues yourself?

Mike
I didn't have them check them. I had the valves done for my peace of mine. It felt like I was driving a $15k time bomb.
 

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I noticed this in another thread...



I see you've done some aftermarket engine work on your Z. Did you have valve issues yourself?

Mike
(Warning!!! Long winded!) Hello Mike. WOW-A never ending thread??! I sure hope not. Anyway, my name is Mike, and though I'm a newbie on this forum, I've been a Tool and Die maker for 38 years. So I have considerable experience in the mechanical arena. I've owned a C5 for many years. The original engine was nearing a rebuild, so I decided to build a different engine, using the LS7 block and Heads. For health reasons, I decided to have an LS7/C6 Z06 engine professionally built. Because the receipts do not detail every single part that was installed, I do not know exactly what was used, only what I wanted, and what the Shop and I both agreed to. With the reputation this shop has, I felt this was acceptable. I am "old school", and believe an engine should be "broken in". So I never used any more than maybe 1/3-1/2 throttle. Then, with around 2,500 miles on the engine, I took a friend on a ride and floored it. It ran great! As I tried to hit 3rd gear, I screwed up and missed it. The rev limiter saved me at around 6,800 rpm, or so I thought. The next morning, while pulling up to a drive-thru window, my wife says "What's that noise" (!). I noticed it also, but it didn't seem too much louder than before, if at all. I told her you have to consider we are 2 feet from a sound reflecting brick wall, which will amplify any noise. But ever since this happened, the car has an occasional "hiccup" while cruising at 60-65mph, occasional being maybe every minute, sometimes every 30 seconds to a minute. This "hiccup" wasn't there before I missed 3rd. gear. Hearing about some of the valvetrain issues the LS7 motors seem to have, I pulled the valvecovers, 4 rocker arms, and 4 pushrods-All Intakes, by the way. I rolled the pushrods on a surface plate, and after a thorough examination, the pushrods are NOT bent. But the Rocker fulcrum's/trunnion's sure seemed "loose". I was told that the Comp Trunnion upgrade was done to each. But they look exactly like my LS1 Rocker trunnion's do. After looking on Comp's website, they are indeed the stock trunnion's! Then I pushed the valvespring retainers back and forth, and I can see some movement. by "some", I would say maybe .005 to-Possibly-.010 max. Considering this is about 2.000 inches away from the valve guide, I assume I may have .001-.003 total clearance. This seems like a lot for only 2,500 miles. My engine has factory valves, valve guides, and, apparently, rocker arms, along with PAC double valve springs. The cam is a Comp Cam, .640 lift int., .646 lift exh., w/238/242 [email protected] lift. The intakes have lash caps, I assume this is because they are made Titanium. I realize the valvetrain won't sound stock. It's the 24hr. "change", the before and after, that concerns me. Perhaps most telling is the wife noticing it immediately! She doesn't always ride in it, and isn't mechanically experienced. But she noticed it right away. NOT good. Or maybe it is-It still runs and hasn't dropped a valve-YET! I think this "noise" may be due to the stock fulcrums. If not, I don't know what to make of it. I have an idea what your response will be. Guess I'm hoping to hear what I want to hear. But in my head and my heart, I know something is not right. I'm going to run a compression test on all 8 cylinders today, and will post the results ASAP. I have not abused this car. Yes-This missed gear is abuse, but certainly unintentional. It is also the only time I have ever missed a gear in it-It's an A4 car!! Please don't laugh (I know-Even I think this sounds funny-Probably STUPID.) I discovered after the fact that I was already in OVERDRIVE and shifted to NEUTRAL!!!!! DAMN!!!!
 

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Response to Grinder. I do not think you could have hurt a stock or near stock LS7 valvetrain from a missed shift, unless you were at max rpm in one gear than then mistakenly hit the gear below it. I believe the stock rev limiter is 7100 rpm on a 7000 rpm rated engine. If you set it to 6800 rpm, that would be conservative. Compression test would confirm status, unless you had a hurt lifter that is not keeping up. I would think you would hear a collapsed lifter or worn cam lobe as upper valvetrain knock or clacking.

I bought my car with about 8000 miles and 2 1/4 years on it. With the original crap Goodyears, I hit the rev limiter a few times as they would spin to redline almost immediately with traction control ON on dry pavement.
 

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Hey all, recently bought my C6Z. Came with 63k miles on it and I bought a 3 year/36k miles powertrain warranty. Should I roll the dice and not bother getting the fix until my warranty is up or should I tackle this problem sooner than later?
 

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If you have a 3/36 warranty from a good insurer don't bother with heads. If it goes, you get a new motor for the deductible.

I bought my car new in '13 and put a GM warranty on it that expired last year. I wanted to have some minor porting done to my heads and just got them back. As long as the heads were off I put in new Ferrea solid stainless steel exhaust valves, new springs, guides, trunion upgrade, valve job and bowl blend. The machine shop charged me right at $2,000.00. I still had to pay labor, gaskets, ARP head bolt kit, de-carbonizing the pistons, new fluids etc was another $1,400.00.

I didn't need to do this, but was messing with the heads anyway so why not just do it all while there. And now that all that work is done I am having to get the ECU re-tuned because the car is running a little rich, about 6-8% so far as we can tell. Until I get the valves to seat I can't get a WOT data run to send to my tuner . So you can throw in another $250.00 for the re-tune. So all done if you tear into your heads plan on spending about $4K. Hope that helps you make your decision.
 

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Just joined and this is my first post. Reason being...purchased an '06 Z about two weeks ago. It's got 21K original miles. In reading some other forum comments over the last few weeks, I saw mention of an issue with the heads. After reading the majority of posts and seeing that many are reporting (sometimes serious) issues with their low miles LS7s, I'm wondering what my best course of action should be.

Not only it's got only 21K miles, whomever owned it prior treated it with the height of respect. In every way, the exterior looks virtually new. I haven't found a scratch or blemish of any kind anywhere on the body, including the front facia (no rock chips). It doesn't look like it's ever once been driven in the rain, as many areas of the undercarriage are exceedingly clean. Point being, I intend to continue respecting and caring for it at the same level it has been.

I think I probably know the answer, but am posting since this thread started 8 years ago and maybe things have evolved (for the better or worse) with GM's stance on the issue with time. While I've kept my ears perked over the years with all my cars, conscious of any abnormal or suboptimal engine noise, I'm not sure I would've noticed only the slightest ticking noise if I hadn't earlier read a comment about issues with the heads. In other words, I'm confident only the most keen minded mechanic would ever feel the motor isn't running perfect. But, I'll hear it on occasion at idle and low rpms.

And with others mentioning that Chevy V8s in general over the decades have been known to have a mild audible ticking, I'm torn between spending $X on a lifter guides QA check since the noise is far from prominent. On the other hand, I can reason that I've got an extremely healthy low miles LS7, and correcting the issue now will keep it healthy for a good 100K miles, obviously.

I also read the varied opinions on GM's attitude; what they should have done, what they have done, etc. One thing I agree with is that there should've been a recall. No major head-scratcher to many who know the only reason they didn't, was their full understanding that it would've killed them financially...to correct an internal engine flaw in the whole fleet. But I can also easily reason that for the original owners, who paid about $70K for their car, specifically because they were led to believe with all the LS7s' fanfare, they were buying an exceptional motor ("hand built", long list of special parts and technology) as part of the justification for laying down the big bucks. I myself believed just that when considering the purchase.

I live in the Colorado Springs area and there are several Chevy/GM dealers in town. I suppose a call to them asking if they'll offer a valve guide health check at little or no cost, supported by the fact that my Z's mileage is so low. Sure it's now 14 years old, but would otherwise be well under the standard 36K miles warranty (or X years always got me, especially being such a relatively short timespan after new. It seems more logical to give a timeline like double of the average miles driven/year "Six years if under 36,000 miles"). Stating I've heard a ticking noise, armed with the mention of the many others on even just this thread alone might help.

I know...long winded, but that's me. I've owned six Turbo Regals (4 Grand Nationals and two TRs), and spent years on forums. Can't help it...just gotta keep flappin'. ;)
 

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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.
 

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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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