As many of you know, I don't fall in to the DEX killed my gaskets. But I looked at everything I have here with a very open mind. I will give all the data I have here and let'* see if this helps us get closer to a answer.

My engine had DEX in it up to 92,200 miles. I know this to be fact as I removed it and I keep good records. The last just over 10,000 miles is on Peak coolant. I switched because I like the green and it'* easier to see.

I looked at my gaskets real close, and they were failing. As you can see in this picture there was some foam but it looks like there was very little mixing of the coolant and oil.


Looking closer one part fell off with very little pressure.


As you can see the design of the gasket gets very thin in the area it broke. This was done to provide room for the different gasket material.


Another view of a different area. This plastic is rigid just like a new gasket and does not appear to be softened in any way, it'* contact point to the rest of the gasket simple broke away.


Here I have removed the rubberized part of the gasket to expose the under side. You can clearly see there are small holes to allow the rubberized gasket to be held in place. This further weakens the support.


Another angle showing how the inner part of the hard gasket material broke away.


Here I was able to remove the rubberized part without breaking away the plastic part. From the looks of all the coolant jacket openings. The flat area is broken and pulled in and the corners still hold.


The rubberized part of the gasket can then move along it'* base reducing the sealing area and allowing coolant to leak from underneath. I see no softening of the gasket what so ever. I clearly see a total failure of the gaskets base. Gasket failures are the result of poor gasket design, not the coolant it'* self.

Your first picture shows how it broke at all the relief areas. From there it'* my guess that it spreads.

Gotta ask yourself..did coolant make the gasket expand and crack at the expansion area that'* built into it? I'd doubt it. Probably more heat or pressure related.

Totally agree with you Bill. The centers broke and allowed the rubber to slide and then loose contact. The seal is lost and coolant can seep past.

did this just happen are these from the meet a few weeks ago?

That'* the gaskets I pulled from my car last week. 102k miles. Stock gaskets are known to fail and should be replaced with new aluminum framed gaskets.

got ya thats in the plans for me as well when i do the lower port

It'* good piece of mind. And really not that hard to do.

i think that it could be a combo of poor gasket design and the dex cool, but who knows. from everything i've herd and seen i think that dexcool is a load of crap.

Who produces/distributes the afore mentioned aluminum-framed gaskets? The more I hear, and the more I see, I'd just as soon get mine changed as a preventative maintaince before things turn ugly. I have had issues with Dex-cool seeping into an engine and causing the rod bearing to fail, so I personally will be switching to the green coolant after the LIM job. Just my opinion....

Aluminum gaskets are currently dealer only parts. Intense and ZZP have better prices than the dealer typically.