Originally Posted By: Sayjac
Otoh, 'I' would not use DexCool in any system not spec'd for it now because of 2eha used as inhibitor. Best example for me, Ford could have easily backed spec'd it's newer car DexCool for all it's vehicles previously using G-05 and at least some those had pressurized tanks (I know 05 Explorer did as example). They chose not to. I suppose one could say that's it's to sell another Motorcraft AF type, Gold in the case of G-05. However, I'm thinking the gasket-oring compatibility (or incompatibility) of Dex with 2eha entered into their thought process. It might not be the case, but why chance using Dex especially now with all the readily available reasonably pricd aftermarket vehicle spec'd AF type choices with no 2eha. And there's always Peak Global Lifetime as an option, Long Life OAT no 2eha.
Here's what I found about the changes Ford made to their engines before using a DexCool type coolant and why they did not back-spec older engines. The link to the article is now dead, but I had quoted the relevant passages.
All engines are not engineered the same and do not contain the same materials, particularly, gasket material. Here is a SAE article that talks about the changes in engineering and materials that were made in new engines, changes that were made to existing lines, and lines that did not get changes due to being phased out. Ford did not back-spec any engines to their new 2-EHA containing coolant for these reasons.
http://articles.sae.org/8242/
Originally Posted By: SAE
Unlike silicates and phosphates, which deplete as they go to work coating the cooling system, OAT-alone formulas have very long service life. But OATs work very slowly, perhaps taking over 5000 miles to form a protective oxide surface. So they are unable to provide the fast re-protection of cavitation-pockmarked surfaces in water pumps.
If a cooling system is prone to cavitation and the vehicle is used in the kind of load service that is conducive to it, the pockmarking increases and can corrode, affecting water pump service life. As a result, Ford has continued with the yellow S-HOAT on the older 4.6-L and 5.4-L V8s and will not change, as these engines are planned for phase-out.
One of the organic acids, 2-EHA, is a plasticizer, softening some synthetic rubbers and plastics, particularly silicone gaskets and the Nylon 66 used for gasket carriers and radiator tanks. This was another reason for the continued use of the S-HOAT in the 4.6-L and 5.4-L V8s. All OAT-equipped engines have silicone-free gaskets and validated Nylon 66 radiator tanks.
Systems with OAT antifreeze are more sensitive to low coolant levels, because the OAT provides best protection when in full contact with coolant passages. The issue is acute with cast-iron engine architectures, but one also exists with aluminum.
For the OAT systems, the sensors combine with improved powertrain computer algorithms for detecting overheating and deploying the limited engine performance strategy Ford has been using to prevent damage to engines if coolant level drops significantly.
Additionally, Ford upgraded cooling system seals, gaskets, and clamps, and it evaluated (reworking where necessary) the assembly line processes to ensure a full fill. Further, the antifreeze is mixed 50-50 with de-ionized water for consistent new vehicle protection across all product lines.
Filling a car with a 2-EHA containing coolant without knowing if the design and materials are validated for it is a fools errand.
Ed
