ANOTHER Dropped Valve in a Z06...
 

Update on post #53

So, I have a C5 coupe, and finally decided to plop down 40k to buy a used Z06. I just bought it in November-December. It is a 2006 DSOM Z06. I am the 3rd owner, the car has 56000 miles on it, and the first owner had done a cam swap and put dual valve springs on the heads. I don’t think they removed the heads from the car.

Story of how it happened (its long, but a good read):
SO, I was driving home from work last night, and I turned on to my residential road. This road is usually empty, and is flanked by preserved wetlands, so there is usually no traffic. I like to goose it here, on occasion. I got through first gear, only getting it to about 5.5k RPM, and then hit second, and probably got to about the same RPM when CIRCLUNK!!!. This was followed by profuse language. (Here is the only good part of this story) Here I was with a coasting heap of aluminum and fiberglass, with a slew of profanity flying out the window, and I thought to myself, “I need to coast as far as I can so I can get it back to the house, but maybe I can make it!” Granted, I was still a mile from home, and this road goes up hill slightly (elevation gain from 60ft to 90ft, which isn’t much, but still uphill), and my driveway has a good slope to it too…I caught all of the green lights, used my autocross skills to negotiate the turns, opened my garage door as early as possible and squeezed under the door by inches! The car stopped with only about a ¼ still sticking out, plenty to enable me to push it the rest of the way. It was AMAZING! I only wish I had this on video.

Story of the tear down:
So I get to work on teardown immediately after I got home, and punched a wall (not really, but I was mad enough). I have done this so many times on my C5 and my dad’s C5, that it is second nature. I get the passenger side valve cover off, and find nothing catastrophic, but I did find some gouges in the head, maybe from a previous failure? I’m not sure. I get the driver’s side off, and it looks fine too. I then start taking rockers off, and what do I get, but rounded off rocker bolts from the previous workers that had WAY over torqued the bolts! Unbelievable! More swearing ensued. I now need some specialty sockets to get these bolts off, so I decide to pull the spark plugs to see if there is any damage to them. The last one I pulled out was the number 1 piston, and here is a picture of it next to a good one.

http://i.pgu.me/UtMsFb46_original.jpg

So, I will post updates and more pictures of the teardown as I go on this thread. I still haven’t heard a definitive fix for this issue, so I am still seeking advice on this front. I feel a little better today, but not by much. I was really depressed last night.

Update on post #53

Sorry to hear about your troubles, hang in there you'll get it sorted out!
I think the fix is to have the heads reworked with new guides.. or something
BTW my 08 z blew the motor going 125 on a "private road" so I know what this feels like.

your not alone,my friend,many of us drop,but my z had to be towed,your gonna have to pull your heads,have them worked and check that cylinder

Ouch man. Yep I definitely think I'm getting heads before I even drive mine again. It's a good thing it's winter here.

I am glad I purchased a 4 year/48 month b2b warranty on my 2006 Z06. I also purchased it in Dec with 20K miles on it. Sucks I can't mod it until its up. In a way I hope the motor blows just to know I have bad valve guides and the other is I hope it doesn't.

Suggestions lol? :lurk:

Pay for an inspection at a GM dealership. I'm under gm warranty for one more month. If they find the valves are good, that's awesome. If they're bad, New heads for free.

Either way, if my engine ever pops I can show that I paid the money to have a preventative measure done and that will invoke some out of warranty repairs good will.

And on top of that I have a third party warranty for 4 yrs 100k.

What kind of warranty? I know it's not a GM warranty. I hope you picked a good one and read the fine print.

Ouch! I am sorry to hear this. I don't know if you could ever convince me to buy a 3rd owner 50+ thousand mile Z06.

Glad you made it home but I am sure your neighbors and other vehicles didn't appreciate the 1 mile long oil slick. :rofl:


Kinda comical to picture you quietly coasting through a green light and sitting on the other side watching you go through it with a smoking spewing car and obscenities flying out the window :D

Dennis fichtners warranty. It's already covered several hose items that needed replacement upon the used vehicle inspection.

LOL, you made me laugh, and that is always therepudic. Thankfully, I didn't leave any oil trails, or smoke. I did leave lots of verbal polution however...haha!

Its from Mercury Insurance Group. Paid little over $2k. Covers everything as long as its not modified. My car is bone stock except the sound system.

Maybe the block is not toast. Did you see any oil under the car?

You just saved me from posting you word for word. A 3rd owner 50k plus mile( and modded ) Z06. This is almost commonplace. No one will convince me that (and im sorry this happened ) that Z has not had the pi_s run out it before your purchase. NO-ONE.. Keep the faith and make her new again:thumbs:

I don't think the mileage is a problem... but this might be...

Especially seeing that they ruined the rocker bolts durring the install.

I have not seen oil on the ground as of yet.

It more than likely will take more than a head redo/replacement. It sounds like you didn't ventilate the block. Did you get a lot of smoke/steam when it happened? When mine dropped the number 1 piston was hammered badly with the cylinder liner cracked in two places, the head of the exhaust valve broke off the intake valve which then got jammed sideways into the intake port with exhaust valve going into the intake manifold. When it blew there was a huge amount of steam/smoke that came about from coolant coming through the cracks in the liner and then pumping out through the intake and exhaust. Both cats had to be replaced due to contamination.

Just a quick cursory estimate by the dealer determined the crank and two rod/piston combos (the stock cast pistons and titanium forged rods come as an assembly) should be replaced, the block replaced and one head replaced. That is why GM decided to just replace the complete engine. They didn't know for sure whether the crank and the other rod attached to the same crank throw were damaged but they didn't want to under estimate and then be caught trying to replace an additional $1000 of parts.

Good luck with the repair.

Bill

Bill,

You are right that I will likely have to do more than just heads. However, there was no steam\smoke or any fluid leakage at all. So I am crossing my fingers that the block is not damaged. Thank you for the best wishes...:)