VetteNoob

Title pretty much says it all....Thanks! :smash:

95AquaC4

I never use distilled water in my anti-freeze. :confused: Used to use it in batteries though.

GlockLT4

The only time you shouldn't use distilled water is when it is not readily available (ie, you blow a radiator hose, have to patch it, and poor in a few bottles of water you happen to have in the back of your car which makes it so you can get the car home without it overheating). Distilled water will not cause corrosion of the aluminum radiator ... tap water with the minerals, chlorine, and other chemicals can corrode the cooling system.


[Modified by Glock'94, 7:24 PM 8/27/2002]

gtsyellow

distilled water is also the choice cooling material for nuclear reactors :jester

PeteL

85, it is not advisable to run DexCool in your engine. Furthermore it is not advisable to run DexCool below 50/50 concentration. Do a search on this forum and you will find the TSB's I posted dealing with this issue. You are correct that higher water concentrations will produce superior cooling, however this approach with DexCool is dangerous for many reasons. This approach works much better with green coolant, but the use of a supplimental silicate charge is recommended to protect the engine.

GM suggests clean tap water to mix with AF, but tests their water at the assembly plants.

Distilled water is better, distilled and dionized water is better yet. The reason is simply disolved minerals that can fall out of solution and begin to clog up your cooling system. Tap water is full of disolved minerals. Dionized H2O has all the advantages of distilled H2O but is less reactive, therefore will cause less harm to engine components, especially aluminum.

RadPolo96

Yeah, never use dexcool unless you have the later year vettes. The earlier vettes were made to handle it.

GlockLT4

GM says to only use Dexcool in '94-'96 vettes. '94 and '95 came with standard 'green' coolant, but you can switch to Dexcool if you wish. You MUST completely flush the system out if you do this though. '96 came with Dexcool from the factory.

Dexcool lasts longer is the reason for the change.

GlockLT4

I don't know why either.. that's just what GM documentation says

poppy

It is my understanding that if you should run low on coolant in the radiator or get air in the lines that the Dexcool will corrode the radiator, thermostat and anything metal. As long as there are no leaks and the radiator is topped off you should be ok.

95AquaC4

So, Dexcool's bad??

PeteL

85, Gm had a great deal of growing pains with DexCool. The whole issue was so they could say they have coolant that does not have to be changed for 100,000 miles or 5 years. Study the changes in the cooling systems since 1996 and you will find many changes just to support this coolant.

Also, it failed horribly in many models / engines. Do a google search on 1996 4.3L Jimmy and Blazer and DexCool. Do a google search on Impala SS Lt-1 and DexCool.

DexCool also gets a lot of un-deserved attention. I don't believe the coolant should be demonised. However it is unstable when out of it's correct envoirnment, which apparently must be carefully designed.

Why not DexCool in an 85 L98? Seals were not designed for it, and may suffer. Overflow system is designed differently, and my allow too much air to enter the system. But most importantly: the Green cooolant that came with your engine uses silicants that plate out on every part of the water jacket and cooling system, protecting the metal even when the green coolant is not touching it. DexCool only can protect when it is in direct contact with the metal; when levels get low or steaming occurs (often) DexCool allows instant rust and corrosion to form. GM has gone to great lengths to improve the cooling system to help prevent the horrible problems that happen when DexCool looses direct contact with metal parts. There is too much to go into here, takes a lot of reading and learning.


But I ask you this: Why do you want DexCool? It does not cool better than Green. It is 90+% the same chemical as green. It's only claim to fame is that it lasts 5 years or 100,000 miles vs. green of 2 years / 20,000 miles.

Texaco and GM both admit that DexCool when used in an engine that did not come with DexCool from the factory only has a useful life of 2 years / 20,000 miles.

There is no reason to use DexCool in a pre 94 engine, and perhaps a huge detrement. Personally I don't think they got the cooling systems right until most recently in the last year or two only.

Finally the failure mode for Dexcool is horrible compared to green. DexCool tends to suspend the rust and corrosion it allows in the worst of conditions and transports this to the worst places where it gets stuck. There is some evidance that it also tends to combine with the suspended guk and form a sort of gel; however this is less clear but perhaps has to do with local hot spots and steaming under certain conditions.

Sorry to go on so long.

Pete

VetteNoob

Perhaps there is a reason the stuff is colored so similarly to rust.... :eek:

Personally I dont know anything about dexcool.

But back to the original question....so distilled water doesnt actually help the system cool any better, but keeps the system lasting longer through anti-corrosion?

Oly

It depends on the quality/condition of the tap water in your area. I decided not to risk it so when I drained and flushed the radiator and block a year ago, I replaced the coollant with a 50/50 mixture of distilled water and antifreeze plus a bottle of water wetter. It regularly gets to 100º+ in this area during the summer..... I have had absolutely no cooling problems since then. (Now watch.... tomorrow the Vette will look like Niagra Falls just because I said that......)

Mez

In addition to tap water having minerals and chemicals that over time could damage the aluminum Pure distilled water is not electrically conductive according to my high school chemistry class. You need minerals/salts to become conductive. With dissimilar metals in the coolant system, a galvanic reactions does occur, causing one of the metals to erode. Boats have a sacraficial zinc block near any alumumium engine parts in the water to reduce the amount of metal erotion due to the galvanic reaction. (Sorry, if my spelling is not 100% but I am tired).

I just conducted an experiment inwhich I tested the conductivity of plain tap water compared to a 50/50 mix of Dexcool /distilled water.

The plain tap water in a glass showed .5m Ohms resistance with the probes separated by 1/4 inch. The 50/50 mix with distilled water showed 2.5m Ohms or 5 times increase in resistance. Unfortunately, I do not currently have plain distilled water or pure Dexcool to complete a proper experiment.

tkrussell

I agree with the distilled water crowd. The fewer salts in the system, the less likelihood of corrosion, and the cost of the distilled water is relatively unimportant compared to the labor costs of a proper coolant change (drain/ flush/ drain/ etc.)

Living in Texas, I run 25% Antifreeze (and Water Wetter) rather than 50%. Freeze protection to 10 Degrees F. This gives significant gains in heat exchange, and lowers head temperatures 23 degrees F for the same coolant temp. More power and less chance of detonation/ spark retard.

chilihed'95coupe

Dexcool=bbbbbad. See link http://www.geocities.com/b_gillie/dexcool_problems.html

yoslambo1@cs.com

i never did? :confused:

Nathan Plemons

I've run dex cool in mine ever since I did the cam swap with no bad affects at all.

The key really seems to be to make sure that your cooling system is healthy and that you flush it completely. In my case I flushed everything completely and installed an electric water pump so I eliminated that seal as a point of failure.

There seems to be just a whole lot of bad hype about the stuff. I've never known anybody to have trouble with the stuff and believe me, I know a lot of GM guys. I even had them put Dex-Cool in my old car after completely flushing it. Normal antifreeze allows for some serious corrosion after a while if not properly maintained. Dex-Cool is designed so that it prevents corrosion longer, thus the longer service interval.

ConeKLR

Ever use water straight from the facut for your iron over an over again.
After a while the iron becomes clogged and you can't iron your cloths anymore. Suppose to use distilled water in the iron. Same apply's for your cooling system.
:crazy: :yesnod:

ConeKLR

Make your own distileld water. Fill up a jug and let it sit for a few days to a week.
:yesnod: :D