Corvette_D

I thought I did all the preventative maintenance on my 2007 C6 Z06 so that I wouldn't have to worry about an engine failure. Unfortunately fixing the heads a few years ago wasn't enough. Recently my car's engine got destroyed. Here is what happened:

All of a sudden I noticed the check engine light flashing. The RPMs were basically staying steady, but if I gave the gas, it felt like I had no power. Then all of a sudden there was a poof of smoke inside my car, and then the engine shut itself off. I couldn't start it after that even though it sounded like it was trying to start. I noticed the coolant was low and that the oil sump tank was overfilled even though it wasn't overfilled before. There was also oil leaking out the front of the car. It looked like it was coming from somewhere near the air filter. It was dripping down in that area.

I took it to a dealer, and they aren't really sure of the cause, but as of right now they're suspecting the oil cooler failed, which led to coolant being leaked into the engine. They said I need to replace the entire engine and more. They gave me a quote that's really expensive. It's like $19k.

Anyone have any thoughts on how I should proceed? I want to fix the car and get rid of it. If that's too expensive, should I just sell it as a roller?

hy_bmw_freak

Best engine out Disassemble and see what it is. Maybe the damage is not as big as it looks. The dealer should tell you exactly what the engine did not suspect a new engine installed.
For the money (19k) you get a good steadfast tuning engine.
How much was the engine running and who worked on your cylinder heads?

MX621

pcguy2u

How did the dealer make the determination? I mean, what is the state of the engine at the moment? Did they disassemble it; pull heads; pan???

dmuellenberg

Sorry to hear about your engine. Obviously there is no guarantee that an engine will never fail, regardless of what you do to it. You had the heads fixed, but it sounds like the problem isn't from the valve guides. You need to find out what the real problem was before you can decide what to do with it.

Corvette_D

I thought that's what they did. The first day it was there, they checked it out and then said they needed an engine specialist to look at it, basically someone who works on engine internals. Then the next day they said their engine specialist said what I posted here, but he doesn't know the exact cause for sure because of how messed up everything is inside the cylinders. Besides the heads, that engine is completely stock. I also got my dry sump tank enlarged this year, but I feel like that wouldn't have anything to do with this.

American Heritage Performance with the Moldstar 90 valve guides. Hopefully my heads weren't damaged because of all the coolant and everything else that went on. I'd love to still reuse them. I'm not familiar with the oil cooler on this car, but I will be looking into this. I'm probably going to have it towed to a different shop.

They said they looked inside the engine internally and that's why they specifically wanted to get a more specialized tech than the one who looked at it when I first brought it there. They said the engine hydrolocked and damaged the piston rods.

I'm not sure of the state of it at the moment. I was just completely in shock and not thinking straight when they told me their take on what happened and the cost to fix it.

Definitely agree, thank you, and I believe I have one of the best (if not the best) head fix there is. I need to get another opinion from another shop I think.

pcguy2u

The fact that the engine turns over brings the hydrolock determination into question. Are the heads of the block?

Landru

I'm w/ the others, while horse is outa the barn now more details fill in a picture.
Start w/ who did the labor? Who rebuilt heads? What was done to said heads? How many miles on rebuild?

FWIW a flashing CEL means engine must be shutdown immediately, like the very moment it starts.
Might've hurt this motor by doing what was done, post-flash.
It's rare LS7 gives any warning & yours did, possibly saving it from more serious ensuing damage.

$19K is $6K less than my local yokel dealer quoted a new LS7, installed. Dealers.
Flat-bed it away from that dealer.
Ideally there's a competent indy Corvette shop's available, take it there. Quote time.
Using a solid shop, while still not 'cheap', the savings will be substantial & well worth the time including tow.
A good shop might even be able to source a slightly used LS7, much less $.

Sorry to hear this, it's my worst nightmare & precisely why I had my heads rebuilt...which assumes your failure's head related
While getting H/C & tune recently noticed there was no warranty, implied or expressed on parts or labor.
This stuff is just nuts and bolts & can fail any time, some risk goes w/ the territory of ownership.
Quickly learned there's no such thing as failure-proof -- heads or not.

Apocolipse

2007 is air to oil cooler...no contact with coolant at all. Clearly their engine guy knows nothing.

Sounds like something went boom, leaked coolant into the bottom end, and oil pump tossed er into the sump.

supermetroid

Damn, that sucks! Sorry to hear, I also have a low mileage 07 ZO6 and haven't had any work done, completely stock...

Corvette_D

Are you asking if the heads are out of the block? Honestly at this point because of the responses here I'm wondering what they checked exactly. I'm not sure if they are out though.

I didn't know that about the flashing check engine light. Thanks for letting me know. I think my only choice is to tow it out of there and have one of the good shops around here look at it. In my opinion, I don't think it would be the heads because I have great heads in there. Someone mentioned to me it might be a cracked sleeve, but when I searched for what causes that, it seems like it mostly happens on cars making much more power, and mine is basically making stock power (had it on the dyno a few years ago). I thought keeping my engine stock besides the heads fix would make that issue never happen to me (of course that still might not be what happened). But yeah, definitely could have failed just because sometimes parts simply fail!

Well that's interesting... I figured they'd for sure know these things since they service and sell a ton of Corvettes.

Well, mine is proof something can still happen even with preventative maintenance. I'm in a very difficult spot right now because of this. Make sure to at least get the heads fixed. In time I should know what failed exactly.

pcguy2u

I think that before you move it to a new shop you should have an in depth discussion with the service manager and the technician so that you can get a full understanding about the condition of the engine and the cause of the issue.

After that you can talk to other shops and get a feel for what they think.

And only then make a decision to move the car to another shop...

Good luck,
Nick

exracer28

Where are you located? If they did not remove the spark plugs and use a borescope to look inside the engine I would do that before taking anything apart. If the oil has water in it the oil will have a milky appearance. If the oil looks normal a broken oil pump will cause the oil tank to overfill and the engine might be repairable. Unless you do your own work selling the car as a roller vs repairing the engine might be a wash. I see 2007s for low 30s and a roller with the engine still in it might get 15. It is not unknown for some owners to put a dry sump LS3 in their cars just to sell it. If you are going to sell it a used engine might be enough to sell it. If you were going to keep it a new crate LS3 installed should be under 10k.
Like other have said I would find out what is wrong before making a decision.

xene106

Sorry to hear about what happened. But from my reading it seems the dealer technician is incompetent. I would take the car to a corvette performance shop. I don't trust dealers really since their technicians aren't really knowledgeable like 80% of the time. Your motor probably is toast but the tech took easy way out to say just replace rather than take the time to actually diagnosis why it failed.

Corvette_D

Thank you to everyone who has written so far. This is really helping me!

Thanks. Right, I'm going to try to get more information out of the tech. I already tried calling this morning, but I think I'll have to wait until Monday because their service department is closed.

I'm in Southern California. I was wondering about it being a wash to sell as roller vs. fix. If I could get a good condition used engine (i.e. one that came out of the car because the owner wanted a different engine altogether, something like that), that'd be great. I don't plan on keeping it at this point, so I would prefer not to put an LS3 in it. If anything maybe an aftermarket 427 or something? I don't know, not sure what my options are, but for sure I want to spend less than the amount the dealer quoted me.

Thanks. Right, I'd at least like to know what the issue is before just replacing everything.

Dirty Howie

Sorry to hear about your motor !
I don't think you mentioned whether you track the car and how many miles on the motor.


​​​​​​​DH

stefuel

I have seen....

Over ported heads that cracked in the port.
Otherwise plain old cracked heads
Blown head gasket
Cracked block/sleeve. This is a dry sleeve so if the sleeve is cracked and coolant got in that way, the block behind the sleeve is cracked.

As stated, coolant can't come from a air to oil cooler.

03BlkZ

Subscribing to see the actual cause

Mark Leger

This sounds like a typical blown head gasket. When those go coolant leaks into the oil. As long as you didn't drive it after it happened, hopefully nothing else needs to be replaced.

moose.b3

You're in SoCal so I would give AHP a call. If you decide to sell your Z, an AHP motor in it would be a strong selling point.