Well, aside (sorry for bringing it up) that there'* a trend to get mad when someone questions a theory, rather than having open discussion...
I'd love to get a real answer on this from the people who made the changes, but with talk of class action lawsuits and such, there'* not much chance the truth will ever find it'* way to the internet. I don't know what the truth is yet, but I'd like to find out one day.
Anyway, Willwren - feedback (what was asked for) from your page:
I have one very large problem with the conclusions that are drawn on your page. The biggest issue I have is this - with all of the variables in place, there'* one that jumped out at me more than the rest - you're comparing S1 gaskets to S2 gaskets the entire time. It'* fairly common knowledge here that S1->S2 was a pretty big re-design. I could just as easily compare nylon carrier gaskets from a different engine architecture and try to draw conclusions. Yes, I know they're similar, but they're not the same
From that point, any A to B conclusions are null.
That said, ignoring that niggle, there'* a few more that caught my eye. There are reliefs cut in the S2 gaskets (no idea why, btw) that from my eyes (and the 4 or 5 S2 gasket jobs I've done) are the starting point for gasket failure... those reliefs aren't visible in your S1 gasket. I don't remember from my own S1 lower gasket replacement if those are present on the S1 or not.
Really, the only way to draw the conclusions you're looking to make are to take 2 engines of the same vintage, throw new gaskets in, and run one on Dex and one on Green. Add 2 years, pull them apart, and look.
Of course, that'* probably not going to happen - the logistics of such a test are beyond most DIYers. That'* something GM would do.
I also don't think we can rule out torque. You mentioned in your article:
2. Over-torquing would show failures around the holes for the LIM bolts in the gaskets. We don't see that, and we know the compressive strength of Nylon is quite high. The failed areas are nowhere near these potentially over-torqued holes.
Failure around the bolt holes would only be evident if we're assuming uniform thickness of the gasket carrier, heads, and LIM. While it'* not likely that any of these are so far out of flatness the cause a problem, I have a hard time generalizing to the point that all torque issues would be evident at the bolt hole location.
Also, for consideration, if torque wasn't the issue, why would GM revise the gaskets to add a powder metal torque preventing ring? Product changes cost money. Adding metal (not to mention several steps to the manufacturing process) to a 100% nylon carrier doesn't happen on a whim - there'* a reason. I don't know what those reasons are, but I think it'* a bad idea to rule it out so quickly.
On page 2, there was mention of the UIM gasket - it'* got the same situation. It'* got Dex flowing through 2 locations, and we don't see the same failure. That was brushed aside because of the gasket redesign, in which the o-rings fully encapsulate the nylon on the carrier - which would tend to agree with your conclusions that the carrier needs to be protected.
But you overlooked something else going on - a biggie. Notice the color of the old gasket material on the coolant port vs. the new? Orange vs black? Those are two different materials. What'* more, with the old gasket, since the entire sealing surface was made of the same gasket material, it was molded as a single (continuous) piece. With the new material, this is not possible
. So then there'* the question:
If you have to change the material around the coolant port (probably because of interaction between the original material and Dex, no less), how are you going to do it? How do you get that o-ring of material to stay in location (and aligned) on both sides of your carrier, while maintaining a gasket design that can be retroactively applied to existing S2 cars?
Well, you make it so that it slips inside of the UIM gasket like a grommet. Side affect? You now have gasket material on the inside of your coolant bore.
I could go on, but I'm pretty tired, and I don't want to give the wrong impression - I think there may be issues with Dex Cool, but when you're looking for issues that may be caused by Dex Cool, it'* easy to ask the wrong questions, or fail to ask questions that should be asked.
I tore apart my mom'* L36 a few weekend ago, with about 40-45k on the clock since I updated it with the pre-revision LIM gaskets (3 years, 4 months). What did I see?
Well, here'* install pictures (from 2004) and teardown pictures (from a few weeks ago):
Here'* a closeup of a coolant port:
No failures, gaskets all in tact. all Dex, and it ran the last month of it'* life before this operation with little to no coolant in the engine. Until the end, that is, when it was re-filled, which gave way to immediate UIM failure (or more appropriately, it had already failed, but had no coolant to show signs of failure).
Anyhew, I think what we're actually seeing in your photos is that the notches that exist in the coolant ports are about how deep the failures (with respect to the fibers) occur.
So, sorry for the rambling post. I'm kind of posting thoughts as they come, and I'm too tired at the moment to make a cohesive statement of everything I'm thinking about. If I had to sum it up, this is what I would say:
I think there may be issues with Dex Cool, but I don't think we have sufficient evidence to say what those issues are (seriously) or what is causing them. I also don't think we should throw up a warning flag and tell everyone they should run green. I've seen plenty of high-mileage vehicles that are running Dex - it may be an issue, but it'* only a part of the problem. Where should we be looking? Well, I'd see if you can track down what material changes were made to the actual sealing materials. I'd also try and figure out what the main differences between the S1 and S2 gaskets are.
But most importantly, I'd start trying to ask questions from both sides of the argument, rather than ignore them. I had to coax my S1 */C back in to health because of massive
LIM gasket failure, and it was running... you guessed it, green coolant. You've asked some good questions, and you've dug up some interesting facts, but you're pretty far from a statistically valid model.
I'm happy to discuss, always willing to listen to other opinions (I've been wrong in the past
), and dig up information when possible - but it needs to be reciprocated. Part of the reason I took a hiatus from posting here is because of the attitudes I still see in posts like this today - even when counterpoints are requested, they're treated as hostile, and the poster gets a wide range of verbal pepperings, depending on their standing here at the BC. It shouldn't be like that.
Just to point out, there'* also class action lawsuits against Apple for lowering the price of the iPhone. There'* class action lawsuits against hard drive manufacturers for (correctly) reporting the size of hard drives, while ignoring the people who are really at fault for the confusion. Law suits are only as smart as the dumbest person on a jury or the judge. And while judges are generally very smart, they're not engineers.
Hey Pat, don't pay any attention to all the lawsuits and information out there. Use DEX in your car. Rolling Eyes
You think all that information is out there for no reason? I understand you have a duty to believe in your Father, but you also have to give credit to State Attorneys and their investigative powers. They're after GM on this because there'* an issue.
The presence of a lawsuit is hardly evidence that an action / product is unsafe / wrong. What'* more, they go where the money is - and GM is a pretty target. If you could convince a judge that all GM vehicles made in the last (how many, 10?) years have coolant that will destroy the engine, how much money are you talking about for damages?
Again, not saying Dex isn't a problem, but we're asking the wrong questions.