Page 1 of 1
Confused about Dexcool
Posted: Mon Aug 31, 2015 6:58 pm
by billyjobob
Just purchased my 98 Safari, going to change out radiator and thermostat. I asked radiator shop selling me the radiator about flushing Dexcool and replacing with universal coolant and they recommended against it saying the new coolant would likely ruin the gaskets
Since I keep reading get rid of Dex here, I'm confused. Anybody have any thoughts on this?
TIA
Re: Confused about Dexcool
Posted: Tue Sep 01, 2015 6:22 am
by ihatemybike
It's pretty simple. Dex is fine when it is not mixed with anything else, especially green coolant. It's people screwing up and mixing the coolants that caused the problems with factory Dex vehicles and caused Dex to get a bad rep. You may run Dex or Green, but you had better flush, cleaner, drive, flush, cleaner, drive, flush, then use whatever coolant you are going to use and stick with it.
I personally stick with Dex and my very high mileage vans have had no issues resulting from it. I see it as a system safety thing. If I loan a van or let a pro work on my van I don't want them to accidentally add something else. Cap says Dex-cool only, so I'd hope that's what they'd use and I'd be able to have recourse if they didn't.
Re: Confused about Dexcool
Posted: Tue Sep 01, 2015 9:25 am
by billyjobob
Thanks Aaron, I am now un-cornfused, will do a simple flush and then install the new radiator
BJB
Re: Confused about Dexcool
Posted: Fri Sep 04, 2015 1:17 pm
by AstroWill
ihatemybike wrote:It's pretty simple. Dex is fine when it is not mixed with anything else, especially green coolant. It's people screwing up and mixing the coolants that caused the problems with factory Dex vehicles and caused Dex to get a bad rep.
According to the manufacturer mixing them is not a problem, seems to be air getting into the system(small overflow tank, mounting, wrong style/type caps) was supposedly the cause of the jelly/goop/contaminant problem. The litigation was that it was eating intake gaskets and causing other problems. Which makes sense if 2-EHA is a plasticizer(plasticizer - takes hard plastic and turns it into a jelly for her pleasure) Take a look here:
http://www.imcool.com/articles/antifree ... GMdocs.php Lots of reading through those links. I guess if you do use it, make sure that you use the proper (new?)cap in good clean working condition and don't mix just to be sure
The simple fact of the matter is that there are way too many issues and concerns about Dex-cool, otherwise we wouldn't be asking about it in the first place. Personally I have flushed each and every one of my vehicles that has come with it and use regular universal coolant. It had eaten away my late 97 K1500 intake gaskets before I knew anything about it, after I replaced the intake gaskets I went back to green.
https://en.wikipedia.org/wiki/Antifreez ... technology
Organic acid technology[edit]
Certain cars are built with organic acid technology (OAT) antifreeze (e.g., DEX-COOL[19]), or with a hybrid organic acid technology (HOAT) formulation (e.g., Zerex G-05),[20] both of which are claimed to have an extended service life of five years or 240,000 km (150,000 mi).
DEX-COOL specifically has caused controversy. Litigation has linked it with intake manifold gasket failures in General Motors' (GM's) 3.1L and 3.4L engines, and with other failures in 3.8L and 4.3L engines. One of the anti-corrosion components presented as sodium or Potassium 2-ethylhexanoate and ethylhexanoic acid is incompatible with nylon 6,6 and silicone rubber, and is a known plasticizer. Class action lawsuits were registered in several states, and in Canada,[21] to address some of these claims. The first of these to reach a decision was in Missouri where a settlement was announced early in December 2007.[22] Late in March 2008, GM agreed to compensate complainants in the remaining 49 states.[23] GM (Motors Liquidation Company) filed for bankruptcy in 2009, which tied up the outstanding claims until a court determines who gets paid.[24]
According to the DEX-COOL manufacturer, "mixing a 'green' [non-OAT] coolant with DEX-COOL reduces the batch's change interval to 2 years or 30,000 miles, but will otherwise cause no damage to the engine".[25] DEX-COOL antifreeze uses two inhibitors: sebacate and 2-EHA (2-ethylhexanoic acid), the latter which works well with the hard water found in the US, but is a plasticizer which can cause gaskets to leak.[17]
According to internal GM documents,[citation needed] the ultimate culprit appears to be operating vehicles for long periods of time with low coolant levels. The low coolant is caused by pressure caps that fail in the open position. (The new caps and recovery bottles were introduced at the same time as DEX-COOL). This exposes hot engine components to air and vapors, causing corrosion and contamination of the coolant with iron oxide particles, which in turn can aggravate the pressure cap problem as contamination holds the caps open permanently.[26]
Honda and Toyota's new extended life coolant use OAT with sebacate but without the 2-EHA. Some added phosphates provide protection while the OAT builds up.[17] Honda specifically excludes 2-EHA from their formulas.
Typically OAT antifreeze contains an orange dye to differentiate it from the conventional glycol-based coolants (green or yellow). Some of the newer OAT coolants claim to be compatible with all types of OAT and glycol-based coolants; these are typically green or yellow in color (for a table of colors, see[16]).
Hybrid organic acid technology[edit]
HOAT coolants typically mix an OAT with a traditional inhibitor, such as silicates or phosphates.
G05 is a low-silicate, phosphate free formula that includes the benzoate inhibitor.[17]