I am reading all these horror stories about Dexcool. Is it that bad? I have an intake manifold leak, is is the problem with the gasket or the Dexcool or both?

 

Dexcool isnt bad if you have good gaskets and its all you use. Most of the time its the gaskets that are the problem, not the dexcool.

 

The problem with Dexcool is that when not properly maintained, and air gets into the coolant system, the organic acid that makes it extended life begins to sludge. This sludge can clog passages, lines, hoses, etc and decrease the cooling efficiency causing serious problems.

What kind of mileage are you pushing, and what vehicle are you driving? It's probably just a failing gasket unless youve got like...30,000 miles on an '05...

 

I should have mentioned I am driving a 2000 Blazer, 4wd with 93000. And thanks for the fast response


Curt

 

Dexcool is good until you get air in the system... The green stuff is a little more tolerant of air... Otherwise, dexcool is better for extended periods and aluminum (assuming you keep the air out of the system, lol)

GM released updated gaskets to help prevent leaks (they're aluminum now)

 

Actually, now most of the green stuff you buy is OAT (organic acid tech). The difference is the green still wets (ie. leaves a layer on the surfaces) while dexcool does not. When a coolant wets the surfaces, it leaves behind a protective coating, but decreases its ability to cool. Dexcool cools more consistently, but does not leave behind this layer. The sludge is not from dexcool alone, but the corrosion that sets in when air is in the system. That is why you do not see these issues as much on aluminum block engines. I'll also mention that you will not see sludge in a system unless it has been very poorly maintained.

One thing that is quite similar is the OAT and what it does to the intake manifold gasket material. Replacement gaskets are available with an aluminum frame that will greatly help to keep this from happening again.

Everything that there is to know about Dexcool can be read in the Dexcool thread (run a search and you will find it). The problem truely lies with lack of maintenance and in the improper choice of intake manifold gasket frame materials used in many of the v6 engines. (3.1, 3.4, 3.8, & 4.3 for the most prevalent failure rates).

 

The majority of people with those engines either beat the poop out of them, or don't know enough about vehicles to keep things in running order, hence, them seeming to have more issues...

That, and I'm sure the cast iron block and aluminum heads expanding and contracting at different rates helps a bit.

The wetting is why people generally thing the green performs better because it "warms up faster"