'06 Quicksilver Z06

Not looking good at this point.

LT5 John

Hey Chad, it is damn shame. It's a depressing state, to see a lot of these stock Z's dropping valves...WTF!...

z0sicktanner

I know buddy. but I figured this would happen. thats why I was posting so much on this issue

JWingo

Man. The plug is disfigured. Met an obstruction. White smoke would be indicative of fluid entry into the combustion chamber. Is the coolant level down in the reservoir? Could pull both rockers closing the chamber and apply shop air. Pulling the rockers may tell it all. But it looks conclusive. Head will have to be removed regardless.

Vettelover2

So if water comes from the oil pan I have a hole in the block? Also, since I have a dropped valve all the metal is in the engine block. So that really means the engine is gone because you can't flush metal out of it.

I really love GM however, I never thought in a 100yrs I would have to replace a LS7 engine and the car looks brand new. This may be it for me on GM. I have had 2 vetts, LS1 ram air trans am and still have my 91 z28 vert.

I am still in shock. I drop the oil tomorrow. If no water what then? Will I still need a new engine? What kind of numbers am I looking at?

'06 Quicksilver Z06

I don't think I've ever seen anything quite like this.

And I was so optimistic too and hoping that the worse was behind us.

Thing I'm noticing, is it's hitting these new guys, or these guys who are not typically in these threads, especially hard.

The original poster of this thread has been here for years, but does not post a lot.

And then cantevendrive75 got hit with it and he is not what one would call a "veteran" of these discussions either.

Vettelover2

A the coolant is full Jwingo!

JWingo

I hate this. Either of the methods mentioned here will be effective in determining your next course of action. Coolant in the oil. Shop air. But my friend at any rate, the head will require removal. Can you remove the rocker cover pretty quick? You may find the answer. I suspect you will.

z0sicktanner

when we talked on the phone last year this was what I was worried about

Vettelover2

Pics of the inside of valve cover. Looks normal. The spark plug cam from the 1 position by the alternator.

Mark2009

Given the way that spark plug looks, that would be a almost certain conclusion.

If no water then the piston may not have exploded, or if it did it didn't hole the block in a water jacket. Beyond my expertise to make any speculation beyond that. I would guess that if the piston didn't explode then you may be able to rebuild if indeed you did drop a valve (and of course that's what it looks like).

One step at a time. If no water in the oil then you need to look inside that cylinder (borescope) or pull the head. Probably time to start thinking about a shop... if you dropped a valve but didn't blow the piston at the very least you're going to need a pro to look it over... that's far beyond a DIY IMHO.

ramairws6

Really, you thought the worst behind us!? I knew we were just getting started. The reason why is that alot of these are weekend cruisers. Or only used on nice days, few and far between, or when a persons not busy with regular life tasks. This might be getting real ugly as we go on but maybe it will
prompt GM to finally step up to the plate

ramairws6

To the OP, so sorry to hear about your car. I can feel your pain...

Mark2009

From what I've read here, a dropped valve is often not obvious from that side of the head.

As to the oil drop, if it's got coolant in it there is no need to pull the head; the entire engine will need to come out. So... easier to drop the oil and see if pulling the head is worthwhile at this stage.
.

Mark2009

Guys, editorializing about new guys or weekend cruisers is not going to help the OP, it's only going to clutter his thread while he's trying to sort this out. Please.

Mark2009

Well I just thought of one thing... pull that exhaust rocker and see if you can pull the spring up, or with the rocker off if it is sitting noticeably higher than the intake valve (take the intake rocker off too in case it is being held open by the cam lobe).

If it is sitting higher, the head on that valve is probably gone.

Could be very inconclusive as carbon and gunk tend to build up at the lower portion of the stem where it meets the guide. So, really no relief if it sits tight where it is, but if it does move up then the valve head is gone.
.

'06 Quicksilver Z06

Did you drain the oil?

Did you check the oil on the stick from the sump tank?

In your original post, you mention "smoke".

I'm wondering if some of that might not have been steam.

Oil or antifreeze, it would have a distinct smell to it.

I remember this case below from awhile back.

Dropped valve, I think he was able to get away with re sleeving the block.

http://forums.corvetteforum.com/c6-z...rop-valve.html

Vettelover2

I will drop the oil tomorrow. Do I need to drop all of it?

Also, the smoke was white smoke like fire no water vapor with water or coolent smell. Same smell on all 8 spark plugs I will leave the rockers alone for now.

In all cases of a dropped valve did the engines have to be replaced or just head work?

Why would the piston explode Mark200x?

SmokinZ

If the valve head is fully detached from the valve then there should be lease pressure to the valve making the "wiggle test" even more pronounced. I know from experience. You might get lucky and be able to resleeve the cylinder. In my case I had water in the oil because the sleeve was compromised. My block didn't "window" but under closer inspection there was a hairline crack in the block around the cylinder and we determined that it was not going to be reused. You will need to take the head off to fully inspect. I took mine off in a couple hours and it wasn't a big deal. You just want to keep some sandwich baggies to put bolts in and a Sharpie felt marker to document. It may be a while before you can get it into a shop and you don't want to loose anything.

To get the best answer right a way is to dump your oil and look for coolant, it will be obvious. Save the head removal for later, you already know you have problems.

Good luck

SmokinZ

You might as well dump all the oil, once it start flowing its messy to try and stop it.

The cast pistons are pretty brittle and with the valve head bouncing around in there it is bound to do enough hits to the piston to at least take chunks out of it. If you were not high revving then the piston might be mostly intact. Mine was split in half because the valve head embedded itself into the piston upside down.