The purpose of this thread is to possibly help when someone is trying to decide if they should quit using Dexcool coolant. Speaking with a mechanic type friend of mine we got into a debate about Dexcool. He was very adamant that Dexcool is not to be used in any engine. The claims being that since it is a living organism it eats gaskets (his words, not mine). He claimed that GM had even put out to change the 4.3L to the green stuff. My research tells me that is an urban myth.

Well, I then prepared in my head my very articulated, fact based, scientific response to correct him. My response was "Nuh uhh!". Seriously though, I tried to explain that I have been learning from the 4.3L Gods at blazerforum.com and there was no way he was correct. I decided to take some time and really dig into it.

After quite a bit of research I learned about the lawsuits, the claims from one side to another, etc, etc. GM did end up settling, though they continue to use their product Dexcool. But everyone knows that settling is just a way to make things go away so you don't have to pay the Battalion sized team of lawyers they probably have.

So anyway I've read a ton over the last couple days on the internet (because as everyone knows, you can always trust what the internet tells you). The best I found that really takes a look at everything from a pretty objective view is actually on a diesel forum. The guy that writes beginning in post #7 of the thread (More Power), which I have linked below, really did a ton of research. Even to the point of correspondences with the National Automotive Radiator Service Association (NARSA). It's a very interesting thread and they specifically refer to our 4.3L engines also.

Here are some of my personal take-aways from not only the thread referenced below, but other things I found:

1. The gaskets that were being used for the LIM off the line were not very good and when you combine that with the low torque of the LIM bolts and a wet intake, you have the seepage problems that plague the 4.3L. But there isn't little critters chomping away at the gaskets. So definitely use the Fel-Pro gaskets that are recommended on this forum all the time for the LIM if you have to change your gaskets.


2. Definitely drain, flush and change your coolant (Dexcool) per GM recommendations. 150,000 or every 60 months (whichever comes first). If you must use a silicone coolant, flush and change after no more than 30,000 or 24 months. But even the latest bulletin I've seen from GM for our engines state that premature engine, heater core or radiator corrosion may result with green stuff.

3. Apparently the brown gunk that the Dexcool fans blame on mixing with Prestone or not doing proper maintenance; and the Dexcool haters blame on just Dexcool in general...is just oxidized iron (rust) from the cast block due to not keeping your coolant level proper. In other words, as long as you never let your coolant get low, you shouldn't get rust. It sound though that you really need to regularly take a close look at your radiator cap. Air is the catalyst in this case and basically we want to keep all our cooling system components "submerged" (for lack of a better word).

4. To continue on the above point, it's not the Dexcool that "eats" water pumps....it's from the sandpaper like result that happens from not maintaining your coolant properly. You end up with rust granules grinding away at your engine/cooling components.

5. Use only distilled water. In another post I mentioned how I saw a test that was done with 50/50 tap water & coolant compared to 50/50 distilled water & coolant. It was really a dramatic difference. One was completely corroded, the other brand new looking.

6. Never mix the two different kind of coolants! Do a complete hard core flush if they ever get mixed or you are changing from one type to another.

There's some more interesting and fun facts, just take read through the thread in the link. Hope this helps in your decision. Me...I'm sticking with the Dexcool & distilled water.

Dexcool vs. other coolants - TheDieselPage.com Forums

P.S. Moderators I think I posted this in the correct forum. But if you feel it should be in the General Chat, please move it. Thanks!

 

Logic and reason will never prevail as haters will always hate, from both camps. Thanks for the comprensive research.

 

Each of these points has been discussed and agreed with many times prior here on BlazerForum. We don't need yet another thread for the discussion.


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