06 equinox 3.4, 120k miles. Losing coolant. Oil was milky. Does chamber with reddish exh valve look a little suspect?
Both headgaskets look ok. No obvious corroded areas.
Looks like the carbon has been steam cleaned from that combustion chamber.
Tester
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Yup That cylinder with the orange valve is the head gasket failure point. I’ll bet the piston top looks clean, too!
Check that head carefully for warpage since you didn’t see a breach in the gasket
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How did the intake gaskets look? Possible the gasket was allowing coolant to seep along the intake runner for that cylinder?
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Is this the 3.4-liter V6?
Aren’t intake gasket leaks more common, compared to head gasket leaks, at least on that particular engine . . . as @asemaster may have been alluding to?
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The intake gaskets are metal/rubber and I think most stock gaskets are plastic/rubber. The seller I got it from said it had overheating issue from the start. He got it for a cheap work car annd only had it for a month or 2. He didn’t drive it. and the person he bought it from said it had new headgaskets at one time. No mention of when. Yes it is a 3.4
The rear head exh manifold drops down to cat and the 2 manifold bolts both sheared off. I’ve seen that before. I’m 90% sure they have not been removed recently. You have to unbolt the down pipe to pull the rear head.
I looked on rockauto, and it looks to me like the factory lower intake gaskets are still plastic/rubber, but many of the aftermarket lower intake gaskets are metal/rubber
It would appear they have indeed been replaced, imo
I can get a used head for $40. Would be different at least.
What does the head need to prep it for installation? Is it flat? How are the valves and springs?
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You can see crud/crap on head surface. Almost like the previous tech did not clean mating surface fully? If this is a replacement gasket I mean.
That definitely looks like gasket residue in the first picture
The sealing surface is now clean, but it still looks a little “pock marked” 
Well, what does a new machined surface look like? The iron block also has a surface to consider also.
I wonder if there’s a product you could use to fill & smooth out those pockmarked areas on the right?
It is a cylinder head resurfacing machine, a type of Mill…
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A resurfacing machine is the obvious choice, but it might not work if there’s a deep void b/c after grinding too much away, the compression ratio would be too high. And a diy’er wouldn’t have access to this sort of equipment. So wondering if there’s a diy’er friendly product that could be used fill and smooth out the gasket-area surfaces yet still handle the heat and pressures?
The machine shop can weld it back up and then machine it back to spec…
A DIYer, just like a Pro mechanic, would take the head to the Pro machine shop and have it repaired correctly…
But you can use a check for flatness at home 1st…
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Dad had a lathe in shop/garage among a ton of tools and neighbor had a Bridgeport. He was a machinist at ibm. Making fixtures and stuff. He could have milled my head. But mill and lathe are both gone. Dad still has nice shop though.
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@Cavell , just curious about your car-repair diy’er history. I’ve always at least done the routine maintenance on my vehicle over the years, & some diagnostics and repair too, but I’ve never removed a cylinder head even once. You seem to be willing to remove the cylinder head without hesitation, so I presume you must have a good amount of experience.
Been wrenching with dad since I was 15. Done a few kit cars and street rods. Many motors. Chrys/fords to start. Chevy too. Got a 3.0 vue 10yrs ago and stumbled into equinox 3.4 issues. Did 1 vue 3.0 head job and didn’t care for the ohc setup.
I fix things. Clean them up. Sell them.
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