i think the lower gasket failure is a series 2 problem period and that DEX as nothing to do whit it after doing 2 1995 that never did see DEX the gasket where just like my 1998 that was on DEX all its life


yes DEX gets acid and will become gooey and block cooling system after few years i will never run DEX in my car anymore

I didn't read the entire thing yet but one things jumps right out at me.

The S1 gasket has metal rings in the LIM bolt holes that will not allow the gasket to be over torqued by much. And the gaskets have obvious differences in construction.

To me it still looks like the S2 gaskets are collapsed due to the lack of those metal rings in the LIM bolt hole areas. And this goes with GM'* engineers 1st S2 LIM gasket revision. Thats when the metal rings were introduced.

That'* a bit far-fetched when I'm looking at gaskets with clear signs of acid erosion, and the materials between the S1 and S2 gaskets are identical. firebuick, you had something else wrong with your car. MOST Series 1 (pre-dex) gaskets last well into the 100k'*. Your car is an exception.

Mike, the L36 gaskets here don't show any signs of over-torquing. Over-torquing didn't cause the acid erosion in the coolant passage, which was the direct cause of the collapsed port.

Yes, the metal crush rings are great, but they wouldn't have helped stop the acid in this case.

I still don't see how you can say that with 100% certainty.
Two of those bolt holes are right near the coolant ports.

i think the only true way to test this and to know 100% whats right and whats not is to get a test motor and do some testing with new gaskets and see what happens.

thats the only true way to take out any variables.

We have seen so many cases where green coolant only motors have been found to have deteriorated LIM'* in 95'*. It is quick to say that it'* Dex only, but tough to dismiss if one is willing to open up to ideas and new thoughts.

I chatted with the SEBF'rs and between beverages Don and I sparked more thoughts about the UIM gasket and some of the ports in the UIM softening.

Mike, go back and look at the pics. The bottom of the coolant port opposite the bolt hole is crumbling away like rotten dust. Over-torquing won't fracture Nylon or cause it to deteriorate, or cause fibers to be exposed, or even cause collapse of the intake ports form the same symptoms.

If over-torquing were the cause, why is the bottom of the port worse? The worst damage on all 4 coolant ports is at the bottom.

What caused the crumbling, etching, and discoloration? What caused the crumbling areas to crystallize underneath the silicone rubber? What caused the erosion?

See what I'm getting at? These are in an 'altered state', not simply cracked and leaking from improper installation.

It'* very easy to try to find other culprits for the failure until you begin to understand the poor material choice GM made in an environment that is proven to become acidic, then see the evidence of acidic erosion yourself. Or in my case, see the damage first, then discover how poorly this Nylon is known to perform with acids.

This is like putting cold butter in a warm pan and expecting it to not melt. Would you use latex paint on your car and expect it to last? No. It wasn't meant for that application. Just the same, Nylon66 wasn't meant for an acidic bath.

Whomever stated that Dex doesn't destory gaskets and heat does is right and wrong. We know heat will destroy gaskets-obviously. But take a LIM coolant O-ring and drop it in some DEX for a year or two (yes I found one I had dropped in a gallon jug of used DEX), the gasket is junk at that point. I beleive hole heartly that DEX is the DEVIL for cars-whomever runs it knowingly-shouldn't call themselves enthusiasts. ENGINE KILLERS!

And just to take an opinion from your own engine, you really should just state what you've seen. I've torn down over 100 of these motors ranging from 12k-246k and honestly the ones that ran green stuff always come apart cleaner with little/no signs of gasket failures.

Call it like it is. jr's3800 and I have been close friends and analytical gearheads for a long time. We're both Cingular/AT&T, and speak OFTEN on the phone. We've been quietly discussing this very issue for almost 5 years now. And each time we see a motor torn down in person or on the Forum, we take mental note of it, and we see exactly the same thing.

There is an undeniable trend, and you won't see it yourself from tearing down a handful of motors. If you watch carefully, you'll start to really see that it'* the DEX cars, regardless of year, and not the green. But you don't need to even see that for yourself if you read my web page.

Nylon66 is proven to be a bad choice in materials in an acidic environment.

i dunno but if youre talking about my upper mine afters 10 years was still like new in fact i install back on my car


also if dex is so bad why is the gasket deforme around the intake port also where there no coolant granted not as bad but the are still deforme .