C7&7

I know this is probably a rookie LS7 question, but what years of the LS7 heads are free from the valve issues?

Was it the '06 and '07's that suffered from the issue and '08 and up are free of it?

wolf8218

Nope. All suffer from it.

GMuffley

It has been observed on all model years.

Unreal

Any ls7 made out of the 2006-2014 range is trouble free. That may need to be expanded if they keep making them for the Camaro to 2015 or 16.

C7&7

Ok great. Thanks guys.

And the bulletproof fix is to just pull the heads and have them worked?

What exactly is the issue with the valves? Guides fail?

Unreal

No such thing as a bullet proof fix. Guides and heads wear out no matter what, questions is how long they last before you need them serviced. There are tons of different opinions. I believe it is a bunch of different things along with variation in parts/manufacturing that causes failures. New guides and a 1 piece valve seems to reset the clock and added strength against a catastrophic failure.

erichg1000

There is no issue.














HAHAHAHAHAHAH

Adam_W

There should be a sticky/FAQ thread up at the top of the forum menu for basic LS7 valve guide questions, in addition to the very convoluted sticky thread already present.

The bulletproof fix for fixing the LS7 valve guide wear issue is to trade in your Z06 for a ZR1. But seriously, the widely discussed fix (many threads on this, such as : http://forums.corvetteforum.com/c6-z...next-step.html ) does bring much peace of mind, as documented failures after The Fix can be counted on one hand (someone correct me if I'm wrong).

Despite a lot of hysteria on this issue, I do think this forum is fortunate to have some forum members who have been very organized and diligent about keeping track of failures and discussing the ins-and-outs of various proposed solutions. I feel like there are a number of qualified shops who can address this issue without fanfare (e.g. in California we have CMS, A&A, RPM, and American Heritage Perfomance all within a two hour drive of one another).

'06 Quicksilver Z06

Good points.

And you are right in that pretty much everything eventually wears out.

Good points.

But to your part in bold, I recall seeing that there have been a few LS9s/ZR1s which have had valve guides show excessive wear.

Adam_W

I didn't know that about the LS9. That sucks.

To be honest, my original tongue-in-cheek comment was "The bulletproof fix is to trade in your Z06 for a GTR" but I realized I'd get flamed for being disloyal so I edited it to ZR1

sublime1996525

Hahaha the GTR house there own issues.

Phoenix1911

GTR = tranny problems, Nissan won't do anything
Porsche = intermediate shaft-bearing failures, Porsche won't do anything about it
BMW = premature crank bearing wear, BMW won't do anything
Ferrari = might catch fire Ferrari says your insurance will handle it - Ferrari passes the buck (well played Ferrari).


Much like my knees, if you want performance out of something (your motor, trans, your body parts) and put it through it's paces, you are going to wear out the weakest or most abused parts first.

I'm getting tired of all the valve train discussions in case you haven't noticed

Unreal

But Nissan revised the trannys, programming, etc and now they are stout. Sure if you buy a 1st year model and use the launch control every light you will have issues. At least Nissan addressed the issues.

Jawnathin

As far as we know, every year LS7 head is in the same situation. The believed fix at this time is to get your heads reworked by WCCH with bronze guides and new valves. Preliminary data and experiences are positive, but we still need more time for validation. Everyone pretty much agrees on this.

The big question that remains are what valves.

Some people choose the OEM Hollow Stem Sodium filled valve, which is what GM uses in the car, but some believe they are too fragile and one of the causes of this issue to begin with. The benefit is that this valve is light and since it is an OEM part, the appropriate weight for the LS7 valvetrain.

Other people opt for solid stainless steel valves, which are heavier, but believed by some to be better suited and more durable than the OE hollow. The downside is that they are heavier and cause more stress on the valvetrain. The belief by some is that stiffer springs can compensate for the valve train while others think they're too heavy and could cause other problems when run at high RPM.

No one has proven one or the other is better or worse. Two very reputable shops vouch for one and not the other, so it is somewhat conflicting. I don't think there has been a failure caused by the valve itself in either scenario once they've been replaced and used with bronze guides, but that doesn't stop people from arguing about it here.

Regarding the other cars, every car has its own set of issues that'll need to be addressed. At least it is fixable on this car. We have a pretty good idea of where the LS7 needs to go, just the details are up in the air.

Unreal

I think most stock valves are good. I think the process capability curve of them isn't where it needs to be so people on the low end of the tolerance get screwed. Since there is no way to test valve wall thickness/strength/etc I would just skip OEM. That is my opinion.

darr3239

Ditto Unreal's response concerning GTRs.

My son is a lead tech with Nissan, and advised me they have had no issues with the engine itself. With the transmission, they dialed back the launch mode, due to guys abusing them, so no issues since that first year. It's just that they cost so much more, and don't look near as good. Most people have no idea whether it's a GTR or an Altima when they see one.

Rupert pupkin

The sticky said "small" 08's and up, but it seems like ALL years. I guess that 1st post should be edited.

psp6158

There is a very interesting thread, "proper oil opearating temp" going on under the Z06 Forum, very good reading and more information on heads...

rockinSeat

After you have your heads rebuilt, get something to address the cold oil warm up issue like an ls9 liquid oil cooler, Dewitts, cooler cover, and possibly an oil warmer if you start the car in cold temps. I believe repeated short trips without ever heating is what ate my car's guides. With fresh heads and warm oil, you'll get a lot of miles out of it.

Coach62

Wow, an actual calm, logical discussion on the matter with no name calling??? How long will this last??

2 important options not mentioned here -

1. Ferrea replacement LS7 valves. They are hollow like the OEM, twice the thickness and the weld is higher up on the stem inside the guide. the are not sodium filled like the OEM valves to save weight.
2. Aftermarket heads, sell your stock heads.

Bottom line is your car is pretty dammed bullet proof with this one exception. Choose a fix and it will be good for at least a few years, if not longer. By then we'll have more data and know which fix is best, but they all are clearly an upgrade.

Personally - I chose the new, updated OEM valves. I am happy with my choice, but if I had it to do over I would have chosen the Ferrea LS7 replacement valves.