[RatPin]

I'm prepping to start my project's engine here soon. It has a rebuilt 1985 350 sbc with iron vortec heads, aluminum radiator. I had bought and filled the cooling system with Prestone Dexcool before doing any research on the product. Now I'm finding that the general internet forum consensus is that dexcool is not only the cause of world hunger, but of cancer too. Should I look at flushing it all and replacing with green and just eating the $30 I spent on it. I have not started the engine yet so I should be able to get it all out through the lower radiator hose.

Is this issue just blown out of proportion by all the interweb herds, or is it something I should be concerned about.

[Richiehd]

I personnally havent heard all that. However its what GM recommends for its late model stuff. Dont mix it with the green. Lasts 5 years or so.

[TMF Lindbeck]

If you used distilled water you'll be fine under most conditions. If you just pulled out the garden hose against the directions that are printed on the bottle you may not be fine

[LATECH]

Dexcool is a poor coolant , it degrades easy after just a few years and leaves a brown muddy looking mess in your cooling system.
It is Fine if you change it every few years , even though it says lifetime.
Lifetime ...really is a farce.
Running it wont hurt, I dont like it because so many people NEVER CHANGE THERE COOLANT and that is where the problem occurs.
It degrades like I described...after a few years, turns to mud.
Glycol .. does not...BUT remember it TOO HAS A LIMITED LIFE.
A coolant may transfer heat well , even after several years of use. Big problem is that the anti corrosive propertys which are more important , are pretty much depleted after about 3 years. So changing the coolant and flushing is really a great Idea. Or drain and refill once a season.
As far as changing it out... Meh.... Wait for a year or two, then do a complete flush and use Glycol,and try to get a low silicate formula if you can spot one.

[T-bucket23]

If you dont mind dumping it, I would. You need to get it all out. If you mix it with green it can cause a mud in the cooling system. Dexcool is not aluminum friendly, this is where gm had all the issues. For a while GM was actually putting in the sealant pellets from the factory to try to prevent the intake to head leaks that all the gm's were having.

[BOBCRMAN@aol.com]

Originally Posted by T-bucket23

If you dont mind dumping it, I would. You need to get it all out. If you mix it with green it can cause a mud in the cooling system. Dexcool is not aluminum friendly, this is where gm had all the issues. For a while GM was actually putting in the sealant pellets from the factory to try to prevent the intake to head leaks that all the gm's were having.

GM is still Bars-Leaks best customer.

[Highball]

I'm an engine builder and I will not use that coolant in anything I build. I even avoid Prestone too. There are some great coolant products out there and neither of these are one I would suggest anyone use. Its only money BUT... think of the time too!
Normbc9

[RatPin]

Which coolants would you suggest?

[Highball]

I like Sierra and a Auto Zone store "green" type. They both work well in most weather conditions and neither are toxic to animals who may try to drink them.
Normbc9

[rx191]

You should be fine as long as you don't mix anything other than dexcool with it. Just make sure the cooling system is topped off and doesn't aerate. too much air will make it foam up and turn to mud. Almost every vehicle on the market today uses a coolant based and the poly-glycol in dexcool. The problems with dexcool had to do with how people where using it. it is not a liftime coolant it's only good for about 2 years or 50000 miles.

I would run it, it's not going to hurt anything at all.

[MouseFink]

Only a chemical flush will get rid of Dex-cool if you want to use a ethylene glycol based coolant . A vehicle with a coolant recovery system should never use Dex-Cool because exposure to air will turn it into orange mud. Dex-cool uses OAT (Organic Acid Technology) instead of ethylene glycol silicates as rust inhibitors and just like any coolant, it should be changed every two years or every 20,000 miles, especially if it is Dex-cool.

After my 1991 S-10 Blazer 4x4 was purchased in the fall of 1991, I have used Prestone anti-freeze concentrate diluted with a gallon of distilled water and I replace it every two years. The 22 year old cooling system is like new. Since it was introduced in 2006, I have used one gallon of Prestone 50/50 Anti-freeze Coolant per car and I change it every two years or less. . It is a 50-50 mix of ethylene glycol coolant and demineralized water.

A 50/50 coolant is convenient to use but you are paying double the price for half the amount of ethylene glycol coolant. Just like any other product, people must pay extra for convenience.

[snakebit68]

Dexcool eats gaskets and seals. I've done so many GM intake manifold gaskets because of that crap. I wouldn't recommend it to anyone. I flushed it out of my new Chevy 2500 hd on the day I bought it and replaced it with green.

[RatPin]

So then since I have not started the engine I should just be able to drain it out of the lower hose and be done with it you think? Maybe put some water in the drain it again before going with the new stuff.

[snakebit68]

Yes, but flush it out really good. I know it sucks but I've seen the damage that crap causes. It really does erode plastic and rubber seals and then they leak, and then it gets where it shouldn't be and then it will causes catastrophic engine failure. (Bearings).

[sbchevfreak]

Pulling the hose won't get all of it. You need to have it flushed, or pull the block drains out, and run water through until it runs clear, and then for 10 more minutes. Dexcool is junk, and is the subject of a class action lawsuit in regards to gasket failure.