[keep_hope_alive]

Originally Posted by Dynamical

Well looks like you'll have it back together soon. That's good.

Thanks for the pics. Would of loved to see the intake valves. I suppose the tech didn't mention exactly what vehicles/motors they saw better performance from after the valve cleaning? In my mind he's probably talking about the general population and we know how they take care of their cars...or DON'T.

With your driving habits of tracking high MPG, I am under the impression you like the AFM/DOD? I bought my car with 2,400 miles and it's had a Range most of that time. I always hear that spirited driving helps the DI issue with intake valves vs driving easy all the time. But like someone else already said, there doesn't seem to be those issues on these motors?

I fully intend on putting a Range module in, but I was honestly curious if my driving habits (daily with a lot of AFM activity) coupled with meticulous maintenance using all recommended fluids would prevent a lifter issue. To be fair, I don't have a lifter issue. So this seems a bit random.

I have been going over all bulletins and there is this procedure (not sure it's what they discussed with me).
https://static.nhtsa.gov/odi/tsbs/20...76607-9999.pdf

[keep_hope_alive]

UPDATE -

Dealer reinstalled the heads with new gaskets/hardware and there are still coolant leaks in multiple cylinders. They are communicating with GM for next steps, they are letting GM make the call. I'll have the loaner for a bit longer.

[Dynamical]

What could be causing it to continue leaking besides an error in the install of it all? The leaks that are present, are they the same leaks from before?

[Chutzpah]

What a nightmare…

[keep_hope_alive]

Originally Posted by Dynamical

What could be causing it to continue leaking besides an error in the install of it all? The leaks that are present, are they the same leaks from before?

Excellent question, and I have the same question into the service manager. The first is, what cylinders had coolant the first time and which have coolant this time?

I have a few thoughts:
1. a bad gasket pair is unlikely, but was a reasonable suspicion for the original failure.
2. a bad install is unlikely because the tech I talked with knows what he's doing and the process is really simple. It's just heads on a pushrod V8. The main thing to do incorrectly is to strip the head bolt threads in the block by not re-aligning them prior to torqueing (the 'ol go counter-clockwise until you feel it seat trick comes in handy). But if that was the case, I would expect different cylinders to have leaks.
3. I know that the gas station that I used less than 1/8 mile earlier shut those same pumps down (TopTier 91 octane) for "tank issues". I told this to the dealer but they didn't think bad gas would cause a head gasket issue. However, the coincidence is pretty glaring. Not surprisingly, the gas station never reached out with details on what they found in their tanks after I gave them my information. Usually, bad gas means the car doesn't run or doesn't run well, but I don't know how it would cause head gasket failures.
4. We know the heads have a slight bit if cupping that GM says is "in spec". But maybe it is just enough to be a problem. This is the likely scenario, but if it's heads why it is both?
5. It is possible that the head bolt threads in the block are giving a bit when torqued, preventing the necessary force to hold the head to the block. I've had to repair stripped block threads before, and the kit I used was derived from the 32V Northstar V8 in the 90's that had similar issues. If this is the case, it would explain why the issue is repeating, and it would mean a new engine is called for.

My main concerns are that the engine I have is compromised. It will never achieve it's original lifespan now that it's been opened up and now that coolant has mixed with oil several times now. That matters to me because I bought a new car so I could control the maintenance and life, and I exceed 200k miles on all of my vehicles. I drive this Camaro daily and travel across the country in it for work, so I buy new so I have reliability.

Obviously, there is a physical issue with the engine, and gaskets can't fix it. If GM just calls for an engine swap, then great, give me a factory-sealed engine and I'm happy, that means I have the equivalent to what I bought. If just new heads are called for, then we have to discuss a much longer warranty because I didn't buy a used car with a rebuilt engine, and I want a 200k engine, not a 60k engine.

My dealer has been great through this, so I'm not upset at any of this, and I am happy to be patient for a quality repair. The engineer in me is what drives me to be hyper-detailed.

[SomeGeoffGuy]

Did you ever check your fuel for water? If you have too much water going into the cylinder, the head would lift when it hydrolocked causing the coolant to leak out. This is going to be a sticky mess if they diagnose it as bad fuel, though, because then it technically won't be under warranty. So be careful bringing it up!

Also, I would never reinstall a head without machining it 0.005. Even a brand new one. Get that PERFECT surface on it. Maybe talk them into letting you throw some GMPP ported stock heads on it?

-Geoff

[keep_hope_alive]

Originally Posted by SomeGeoffGuy

Did you ever check your fuel for water? If you have too much water going into the cylinder, the head would lift when it hydrolocked causing the coolant to leak out. This is going to be a sticky mess if they diagnose it as bad fuel, though, because then it technically won't be under warranty. So be careful bringing it up!

Also, I would never reinstall a head without machining it 0.005. Even a brand new one. Get that PERFECT surface on it. Maybe talk them into letting you throw some GMPP ported stock heads on it?

-Geoff

Good point, as I've stated, that was the first thing I told them to do - test the gas. I got Top Tier 91 octane gas, tho, so there isn't anything GM could say since I followed their recommendation (we don't have 93 octane Top Tier near me). I also follow the AC Delco gas treatment per oil change recommendation.

I don't think they even disassembled the head while they had it off, if they did, they didn't tell me and it seemed to go back on pretty quickly after I saw it.

My hope is for a resolution that recreates a sealed factory engine in terms of reliability. It makes enough power for me, as my build log shows, I am making it more comfortable, not quicker. That said, after 100k mi, then fun can be had if there's no more warranty and this is no longer my daily.

[Dynamical]

If I'm understanding correctly, you don't believe they checked the head for flatness? What about the block? Maybe I missed it sorry. But if they did not check for flatness then that goes under the error of install I was talking about. If they didn't check it, I would just assume it would leak again because it already did. I highly doubt they didn't check though, that would be really bad.
I am with SomeGeoffGuy though, I would want that head nice so it leaves absolutely no doubt.

[m6-lt1]

https://www.camaro6.com/forums/showt...php?p=11100963

[keep_hope_alive]

Originally Posted by Dynamical

If I'm understanding correctly, you don't believe they checked the head for flatness? What about the block? Maybe I missed it sorry. But if they did not check for flatness then that goes under the error of install I was talking about. If they didn't check it, I would just assume it would leak again because it already did. I highly doubt they didn't check though, that would be really bad.
I am with SomeGeoffGuy though, I would want that head nice so it leaves absolutely no doubt.

They did check flatness and found the heads to be dished in the direction of width by 0.0015 or so. GM said that was within spec. No effort was made to flatten the heads, to my knowledge. They check the block and said it was perfectly flat. Dealer is letting GM make the call of what to do next.

[keep_hope_alive]

Originally Posted by m6-lt1

https://www.camaro6.com/forums/showt...php?p=11100963

Thanks for sharing. These are stock heads on a stock motor, the dealer was the first to crack it open. What I found interesting was this comment:

Originally Posted by KingLT1

LT4 heads do not seem to have core shift issues like LT1's.

I'd like to learn more about this comment and how it applies to the new aluminum heads. The term is straightforward, as it refers to a defect that occurs when the internal mold cores shift in relation to the outer mold cores as the mold is filled. I don't think the dealer measured to check this.

[ctrlz]

Originally Posted by keep_hope_alive

Dealer reinstalled the heads with new gaskets/hardware and there are still coolant leaks in multiple cylinders.

Hate to say it, but I think you better push for a new engine. This is not going well, and you are not getting adequate explanation of underlying issues. By adequate explanation I don't mean excuses, I mean something that makes sense.
We've all seen the work you do, and I can't see this being up to your standard.
Both the workmanship and the explanations are lacking at this point, so I'm thinking the only satisfactory conclusion is new engine. This is not a criticism, as I would feel the same way.

[MT-SS1LE]

Sounds like a nightmare, hope you get it resolved soon. I know with my OCD, and being a new car, I would never completely trust a dealer repair of this magnitude. What are the lemon laws like in IL?

[keep_hope_alive]

UPDATE:

Service manager got back with me after he returned to the office from vacation. I wasn't aware he was out, and it explains the delay in details. I stopped in a few days ago and a service tech gave me a printout of all of the parts that have been installed and work performed. The parts lists aligns with the single use parts, so the repairs are following GM instructions (trust but verify). The manager answered my questions and gave me updated information. I have been very happy with my dealer, and having a new SUV as a loaner (i've already put 2,000 miles on) means I'm not put out.

GM had the tech use dye to look for the source of the coolant leak. It was mostly in Cylinder 5 with traces in 6, 7, and 8. It is unlikely that both head gaskets are simultaneous sources, and more likely an issue with block casting. They cannot see exactly how it's getting in.

The service manager said he has requested a full engine replacement from GM and we'll hear back in a few days.

This is the best scenario, at this point, given how contaminated the oil has become through the process of head removal, reinstall and coolant contamination. Now we just wait. At least I get to go through the break-in process again...