Yep, that's one ugly website. Looks like it's based on an old HTML template circa 1997.
Lots of good info there.
But it's hardly "new". This link has been posted on BITOG boards several times in the past. It's a couple years old... and you'd have to read it pretty selectively to conclude that there's no inherent problem with Dexcool. This looks pretty danming to me:
Quote:
Expert witness: DEX-IMG incompatibility well-known
One of the documents is from a 50-year veteran of the gasket and seal industries. A member of the SAE, ACS (American Chemical Society) and ASTM, the latter of which he served on the D15 coolant committee, he states that he was aware of GM’s 3.1 liter, etc, IMG failures well before learning of the lawsuit. He goes on to say that the gasket’s poor design and incompatibility with DEX was well-known in his industry. What brought up the discussions was GM’s adopting DEX in 1996, which of course led to widespread testing by him and peers. Those companies included heavy duty manufacturers Caterpillar, Cummins and International. He authored two technical papers, derived from thousands of hours of testing, focusing on the effects that DEX’s corrosion inhibitors have on rubber and plastic gaskets and seals, including GM’s IMGs in question. He concludes that the two are incompatible because DEX OAT inhibitors degrade both silicone and nylon, of which these gaskets are made.
For more specifics, the IMG is described as Nylon 6,6 carrier, 33% glass filled, injection molded, single silicone sealing bead. This man felt the IMG was not a good design to begin with, and then the inhibitors start attacking the weakened carrier. Evidently, because the silicone sealing bead is not molded over onto the carrier, the carrier is in direct contact with the DEX. Tie that in with no compression limiters, needed to maintain gasket integrity (see photo above), to begin with and that, according to the expert, is why the gasket is prone to fail.
Expert witness: HOATs do not degrade gaskets
Interesting, this expert witness went beyond the DEX problem to clarify that different from DEX OATs, HOATs, Hybrid Organic Acid Chemistry coolants, do not degrade silicone and nylon gaskets. The explanation is quite simple; the added silicate inhibitors of the HOAT protect the silicone polymer from the type of degradation it suffers with pure OAT (DEX). (I think I need a Chemistry refresher.)
Any regular around here will know my opinion of Dexcool (I wouldn't use it if the stuff was free). Dexcool's gasket-eating properties are well-documented. Dexcool's sludge problem (whatever the exact mechanism) is well-documented... and the problem is inherent enough that GM has had to pay out thousands of class-action lawsuit payments. I've yet to see any other coolant have sludge problems on a scale anywhere CLOSE to that of Dexcool (can anybody point out any other modern coolant that has turned to sludge in tens of thousands (maybe hundreds of thousands?) of vehicles?).
Perfectly effective and trouble-free alternatives are readily available... so I'm just not sure why anybody would voluntarily put dexcool into their cooling system. But it's a free country (or so I've been told). Do what ya' want.
