DEx Cool Problems

[liv2hunt]

Hey fellas a just flushed out my radiator and put Dex cool back in. My fluid came out clean. Some guy at work told me Dex Cool is awful and all my gaskets are rotting as we are speaking. Has any one had problems?? My Silverado has the 5.3 liter.

[jrose7]

I haven't heard anything other than my dealer said that the fluid was good for 5 years or 100,000 miles.
jack

[silveradotrailblazer]

Never heard any problems with Dex Cool only. I have seen where people have mixed Dex Cool and other coolants (green) with it and it turned almost like jelly and the gaskets did leak then and the truck overheated because the coolant couldnt flow. The guy who mixed em didnt want to spend the extra money on Dex Cool, you know the rest.

[Dr_Zero]

Here is a whole thread about Dexcool with pics of the damage.

http://www.gmtruckclub.com/forum/showthread.php?t=20161

It has been shown to eat the plastic on the intake manifold gaskets and I have 2 trucks that I have seen the gaskets first hand that it has. Ford tried it also and had issues also its just not a GM issue.


"All DexCool-approved coolants to date use two organic acid rust/corrosion inhibitors, one called sebacate, the other called 2-EHA (which stands for 2-ethylhexanoic acid). These organic acids are very stable and last a long time, although they take thousands of miles to become fully effective in protecting coolant passages.

The inhibitor 2-EHA works well in hard water and is more effective than sebacate at lower pH levels (when the coolant moves from the alkaline end toward the acid side), particularly for cast iron. Well, GM has a number of cast-iron engines. When there's a low coolant level in the coolant passages, the exposed cast iron rusts. Apparently, that rust is washed away later by flowing coolant, and is deposited in the heat exchangers. It eventually produces the rust powder problems that have been so widely observed (see MOTOR's August 2002 issue at www.motor.com). Why does the coolant level in these engines drop? The original radiator cap design was blamed for some of the issue, but there probably are a number of causes, including owner neglect and normal seepage. However, the rust powder issue is not a problem that was observed with the previously used conventional American coolant.

The inhibitor 2-EHA poses another issue: It's a plasticizer (softens plastic), so it has been blamed for coolant passage gasket leakage. Softening (and the resulting distortion) was reported by Ford, which encountered gasket leakage problems when it tested a DexCool-type formula on its V8 engines. Ford also saw similar issues with other gasket materials. That killed the OAT coolant idea for Ford, which had used a DexCool-like coolant in the '99 Cougar V6.

Could that inhibitor be responsible for the intake manifold coolant gasket leakage on GM 60° V6 engines? Or is there some other service issue involved? (After all, GM isn't the only one with coolant gasket leakage problems.) The experts are still working on it."