chris2000

Hi guys!

I checked my VGC an my `07 Z06 with 20kmls on it yesterday and it was awefull, horrible. And i was so happy to take the time and do the VGC job. I DID NOT hear any abnormal noise from valvetrain and thought everthing is ok. I just had the idea to get it checked and sleep well. Now the heads are completely off and i can sleep like a baby again.

I think ALL LS7 (no matter what year or how many miles or which driving condition the car got) do have this problem. So get your LS7 VGC checked and save a lot of money!! DO NOT ignore the problem like "it won`t happen to me!" or "i do not hear anything" or "the guy over there told me there is no problem".

This is a serious problem from LS 7 exhaust valves and i think the same valves are in the LS 9 engine!






All luck to you guys and get your VGC checked.

Chris

chris2000

exhaust valve from Cyl No 1, No 8 looks about the same! I checked my VGC and saved the engine from a dropping valve ! Why wouldn`t you do it?

erikszr1

welcome to the club. glad your ok now!

ramairws6

Surprise, surprise.......

jedblanks

You can see the valve stem is worn also, further adding to the issue.

'06 Quicksilver Z06

This is why I'm against any "fix" which would include the used exhaust valves.

Were this a warranty repair, it would be at GM's discretion as to if these same valves ended up right back in some poor sap's car before they sent him on his way after telling him that his heads were fixed.

rfopt

Is this decision on whether or not to re-use the old valves made by the dealer service tech/manger or is this decision made by a GM rep?

'06 Quicksilver Z06

I don't know for sure, but I don't see how one would be consistently any better, or worse, than the other depending on who was holding each job.

If you wound up at a dealership with a less than average service/tech, but an above average GM rep, and the deciion was to be made by the service tech, you're S.O.L.

If you wound up at a dealership and the opposite situation existed and the GM rep was making the call, you're no better off.

Bottom line is, if you wanted all new exhaust valves, and they insisted that your old ones were ok, even after running in out of spec guides, then you'd get to pay for new stock exhaust valves for your "warranty" repair.

Mark2009

Wow! First time I've seen galling on the top end of the guide

Can you take a close-up photo of the top of that valve stem? I'm curious if the rocker was riding off the edge of the stem to put that kind of side load on the stem.

Mark2009

Chad, you don't know what valves the 'dealers' are or are not reusing (or even if dealers are doing the actual 'rebuilding' of the heads).

Can we please have a thread of observable facts instead of wild speculation? Just once?

Dugmole

Tell us the dealers protocol for these issues, other than denial.

If your stance is that his statement is wild speculation of what dealers do or dont do please enlighten us.

I can tell you my experience is pot luck. More than likely they are just installing more defective heads, that is if there is a problem.

WhiteDiamond

I agree with that statement for the most part. Interesting the Darin told me my exhaust valves actually looked very good and "could" be re-used. He won't use a hollow stem valve in a head, but he did mention it. 10K miles on mine and it had really only started to wear in.


**** POOR idea.....Just my .02

WhiteDiamond

I know two different scenarios have taken place for a FACT:
1: Member on this forum got GM to do the test. Out of spec. Ordered new heads. Dealer got heads with NO valves in them and swapped valves, springs, retainers.

2: Not a member on this form took Z to dealership and got same test same result. Dealer, different dealer, ordered heads and got complete heads assembled. Installed on Z.

Both of these Zs were done here in Texas, but in two different dealerships in different cities. Both have been done within the last 8 months.

Dirty Howie

OP, thanks for the data and clear video.

Did I miss it or did you not state what you did on new heads?


DH

Mark2009

If you know for a fact that the dealer is the one that installed the valves (and not a local machine shop) then you have exactly one example of a dealer installing valves in a head (which is a simply horrendous idea, and unfortunately I think I have also heard of an example of this occurring).

Chad's comment would lead one to believe that it is a widespread practice, and that clearly defective valves such as the one in the photo are being reused. That was the point of my post.

Now if everyone can put their soapbox back in the closet perhaps we can get some more info from the OP.

chris2000

Hi everyone!

I am going with new SS Exhaust valves, new bronze guides, new springs, polished used intake valves and one new intake valve! See pictures




Kind regards Chris

vvlf

Why are you having to replace all the stock titanium intake valves ?? Did they have significant wear on the stems all the way around ?

chris2000

No just one new intake valve! See picture! All are going to be polished, because the OEM Surface is not smooth enough for bronze guides!!

erikszr1

dont do it chad.......LOL

jedblanks

All 8 of my exhaust valves looked exactly the same as this one on the stem.