Thread: How many people still use Dex Coolant

The coolant filter is a great thing and I'll never own another car without one. That said, Dex Cool, once it forms its beach sand sludge is proving to be very persistent. But it seems to flake off little bits here and there which then get caught by the filter. The problem is that it appears that sandy sludge builds much much faster than I had previously thought. Im pretty sure I'll find more of it around the #6 cylinder once I get that head off.

But the coolant filter is a great thing and I love mine and I'll have one on my vehicles from here out no matter what coolant its running. If you stop and think about it, everything else has a filter; transmission, fuel, oil, why not the coolant.

Some will argue that the cooling system is a closed system and doesnt need one. I submit so is the transmission but it still has one.

Dexcool sucks period! Best thing I did for my GPs was to get rid of DEX cool. I run Peak Global in both of my GPs. My TBSS unfortuneitly was factory filled and still has Dexcool in its system. I plan on switching it very soon, providing I won't **** myself out of the 5/100,000 powertrain warranty...

I flushed the DexCool out this spring, and have flushed it again since then. The car runs closer to the thermostat temperature, and the coolant temperature remains more consistent now with the yellow stuff.

If you can afford it, Propylene Glycol tends to be a bit better for anti-freeze. It actully reduces the amount of aluminum lost in a system. The trade off is that it is definitely more expensive and requires a higher concentration to get the same anti-freeze levels.

Standard green here.

When i had the prix it say green. Dex always ran about 10-15° warmer then standard coolant.
I remember one time we had the coolant flush machine (pressurized) and took 5 flushes to get it to come out greenish.

Both my wife's and my car are switched over to Prestone Mixes with anything Coolant. I guess it looks yellow. But I flushed and filled both systems. I did this because my other vehicles are all green or the new stuff. So it is much easier to have one kind of coolant in the garage than two. When I need coolant, I just grab a bottle and pour it in. Don't have to worry about getting the wrong kind. I try to do this to simplify the amount of crap I have in my garage.

I had to flush out both of my Grand Prixs and then the 97 Camaro RS. I hate the stuff. If you still have it in your car and you got some time pull your thermostat off and see how much buildup you've got just in that one area. Then tell me you don't have a reason to switch.

Originally Posted by beastin1

if your still in question about dex cool, then ask your local dealer if any of the new cars come with dex cool in them....they don't, it's not been in any new cars since 04....

Total lie. I worked for a dealer and it's still used to this day. It's even used in the Corvette ZR1 and is now used by other manufacturers than GM. The brand new Malibu my girlfriend test drove the other day had Dexcool in it. Said so on the cap.

Dexcool has problems in our cars because our gaskets from the factory suck. If there were no leaks in the coolant system (even small leaks you can't notice), it won't do that. That's why the only cars that have trouble with it have leaky gaskets, and what's even funnier is that people blamed Dexcool for the gaskets too. .

Dexcool is not the problem if it's forming deposits. You have issues elsewhere and Dexcool is reacting with it.

Point is that plenty cars are out there running Dexcool and will never have that problem. So how can it be to blame?

Originally Posted by Sabrewings

Total lie. I worked for a dealer and it's still used to this day. It's even used in the Corvette ZR1 and is now used by other manufacturers than GM. The brand new Malibu my girlfriend test drove the other day had Dexcool in it. Said so on the cap.

Dexcool has problems in our cars because our gaskets from the factory suck. If there were no leaks in the coolant system (even small leaks you can't notice), it won't do that. That's why the only cars that have trouble with it have leaky gaskets, and what's even funnier is that people blamed Dexcool for the gaskets too. .

Dexcool is not the problem if it's forming deposits. You have issues elsewhere and Dexcool is reacting with it.

Point is that plenty cars are out there running Dexcool and will never have that problem. So how can it be to blame?

First off, I don't lie!!!! I personally never take my cars to the dealer because they rob you blind and do lousy work, If they still are using it then my appologies for any inaccuracy, my information must have been wrong and perhaps i was mistaken on that one point....did you even bother to look at the links i provided?? especially the first one...so since I'm lying i must ask then, what is the brown sludge that is found only in cooling systems that use dexcool??? and why did gm settle a class action suit if nothing is wrong with it??? and why does every intellectually savy mechanic I know firmly oppose using dexcool??? In my research i have found only a couple people that say dexcool is fine,(with you it's 3) but that number is vastly multiplied by those that have had problems.... In my opinion dex is garbage, i will never use it and will flush it out of any vehicle i may purchase that has it inside....so to each their own....

with that said, does anyone know the proper flushing procedure??? i checked the write up section and found nothing, if anyone knows maybe they could put something together.... I usually just pull the bottom hose and drain, the drain plug has a wierd fitting that takes a tool i've never seen before.... maybe it requires a "DEX TOOL" hahaha lol....

Originally Posted by beastin1

especially the first one...so since I'm lying i must ask then, what is the brown sludge that is found only in cooling systems that use dexcool???

A reaction between Dexcool and any trapped air in the system or oil. Due to leaking gaskets.

Originally Posted by beastin1

and why did gm settle a class action suit if nothing is wrong with it???

Because it's cheaper to settle for this than pay legal fees when people keep coming at them. Look at the list of affected cars and all those engines are known for gasket issues. They took the smartest (cheapest) way out.

Originally Posted by beastin1

and why does every intellectually savy mechanic I know firmly oppose using dexcool???

Because they don't know the real reasons behind why it fails. Or they're so set in their ways that anything new is the "devil" and will not work. Green stuff was dropped because it will adversely react with aluminum. Guess what, your engine has aluminum parts.

If you take care of possible leaks, keep your system well maintained (no air), Dexcool will be fine. But I will not use the old green stuff. I don't need it corroding any aluminum parts. If you have some sort of grudge against Dexcool, so be it. Use the universal Prestone stuff.

I too will not use the green...I do use the universal prestone.
regardless you have yet to give me solid reason as to why dexcool is good, in fact you have only convinced me further of it's problematic issues, say its faulty gaskets, well perhaps the gaskets are faulty because of what they retain.... and yes the acidity is caused by the air getting in, but wouldn't you rather use something that doesn't turn to acid????
once again i will post this just this one link, i know the guy who took the time to put it together.... please check it out, and read through everything...same type gaskets, with the dex ones having much lower miles then the other and yet they look much much older.... the results speak for themselves
The potential role of DEX-COOL®

Originally Posted by beastin1

well perhaps the gaskets are faulty because of what they retain....

Dexcool has not caused issues in other cars besides the 60* V6 family and the 3800. Two families of engines known to develop leaky gaskets no matter what coolant you run.

Why doesn't it leak in the Corvette? The Solstice? The Tahoe? The Escalade? Saturns? The list goes on. It is because of faulty gaskets and Dexcool is the scape goat.

Originally Posted by beastin1

and yes the acidity is caused by the air getting in, but wouldn't you rather use something that doesn't turn to acid????

This is true. Whenever I need to add coolant, I add the Prestone. But, I haven't been in a rush to flush because my Dexcool isn't giving me any problem because I keep it well maintained. I'm probably a little over half and half between Dexcool and Prestone by now since I did my gaskets.

I have seen that link before, and I've seen gaskets like that on a L67 that had the Dexcool removed after five miles. Those gaskets fail like that, end of story. Not because of Dexcool, but bad design. I refer you back to my argument of why every GM engine doesn't have gasket issues then? The same material was used across the board.

Originally Posted by Sabrewings

Point is that plenty cars are out there running Dexcool and will never have that problem. So how can it be to blame?

Then GM needs to buy me better gaskets to use or not make it a requirement on the warranty.

as far as every gm I must refer you to this link....Consumer complaints about DexCool in GM Engines
and yes most are that of 3800 motors but many are not, I know of people who have switched out the coolent immediately and had no issues whatsoever.
if it's a combination of the gaskets being faulty and the coolent potentially reacting poorly with these faulty gaskets then why not do what you can to prevent such costly incidents?? flushing coolent is much cheaper and less time consuming than replacing gaskets, wouldn't you agree?
if you read through just the posts here you'll find descriptions of inconsistent temp readings being remedied by simply making the switch, for that reason alone i believe it to be a good idea, wouldn't you agree?
i remember something my dad used to say about an ounce of prevention......

Originally Posted by beastin1

as far as every gm I must refer you to this link....Consumer complaints about DexCool in GM Engines

First one is a Northstar engine. Shockingly high percentage of head gasket failures. Just a vice of that engine.

Second is a S10 pickup. He doesn't mention what engine, but judging by the price paid it's most likely the 4.3L Vortec, which I had a head gasket fail on my 1994 4.3L which was green stuff.

Then, 3800/60*, followed by a 3800, followed by a 3800, followed by a 3800/3400, followed by a 3800/60*, and the list goes on. Hmmm... noticing a trend?

Again, show me the engines not known for gasket issues. If it was Dexcool, they'd all have gasket issues. Yes, Dexcool can react badly to contaminants in the system, but it's still a superior coolant. Lasts longer in a maintained system with less degradation and no danger to aluminum parts.

People try to give it such a bad rap it's ridiculous. An old exercise in logic that pertains to this situation comes in mind. Someone completely new to this planet shows up and starts walking around. There's a fire somewhere. They hear all the sirens and run to see what is wrong. They see the fire dept there. Same thing happens the next day, and the next. Without knowing much about our world and our society, they logically conclude that since they see the fire dept there every time the fire dept is starting fires.

People blame Dex because it can fall victim to other problems elsewhere, but it isn't the original cause. Like I said, I put the yellow stuff back in. But when people start accusing Dexcool as being the root of their problems, I have to say something. Those people just don't understand what really happened. Since it is possibly such a problem, I'm going to start driving around on wooden wagon wheels again because something sharp on the road might give me a blow out. If I did have a blowout due to a piece of wood covered in nails and ****, I could blame my car running of the road on my tires because they have the potential of being punctured.

I'm done. I've seen this case fought out several times. Fought it enough myself. If you want to believe Dexcool is some evil creation, go right ahead. The people who designed it are smarter than both of us, so it's all moot anyway.

I will revert back to my earlier argument. DexCool to me is the culprit for the simple reason of its sensitivity to air. Never ever before have I had such an issue as I have had with DexCool. No other coolant I am aware of, even other manufacturers long life coolants, have this issue.

So whether or not Dex Cool is the specific culprit, the fact remains there was never such an issue with the previous generation green coolant nor any of the non-GM long life coolants I am aware of. The fact that such debris and sludge can build up in an engine, even if it is due to leaking gaskets or air infiltration, such as that which I posted earlier in this thread is cause for alarm. The fact it does not occur with any other coolant I am aware of throws the suspicion at Dex Cool.

Now, that said, one thing I noticed and I believe was discussed even on this forum, with regards to the air contamination, was the position of the radiator cap. In its current position on the 3800 engine and others that I have seen, you cannot possibly fill that radiator to such a point that there is no air in it, even if you do bleed the system.

Once that point was brought up I began researching that and guess what. Jay Dankovich of General Motors even brought this up in a convention in 2001 in Orlando Florida. So the fact remains that Dex Cools sensativity to air again points to it being the culprit. Anyone ever tore down an engine that ran any other long life coolant or green coolant that had the sludge in it that mine did or had the deposits and slugde that others have experienced? Not that I am aware of.

In all the research that I did way back when, and it was alot as I wanted badly to put to rest this argument one way or the other, I came to a few conclusions:

1. Dex Cool is HIGHLY, maybe even ABNORMALLY sensitive to air.
2. Some cooling system designs have inherent design flaws that not only promote air intrusion, but make it nearly impossible to get rid of.
3. The design flaws in gaskets, predominantly in 3800 engines further aggravated the air intrusion issue.

Now, I alieviated my air intrusion issue. I did this by using a coolant filter on the outlet hose, on the drivers side of the radiator. Because this hose is higher than the radiator fill neck I can now fill the radiator completely. So much so that I no longer have to bleed my system when I drain the coolant.

So one can make all the arguments for or against Dex Cool that they want, but the fact remains that, even if its a set of circumstances coming together such as the use of Dex Cool and air intrusion or gasket failure, no other coolant has demonstrated the destructive properties under such conditions as Dex Cool has.

I have heard countless reports of 'etching' caused by Dex Cool. It wasnt until I pulled the heads off my engine and saw the crap that was trapped in there that it made sense. Its not the Dex Cool per se, rather it is the sediment that it deposits in a cooling system once it sees air exposure and that grit circulating within the engine and cooling system.

While I agree that DexCool by itself is not necessarily a problem. It may run fine in many vehicles. But it won't in mine. With increasing miles, I get problems. One of them is keeping everything sealed up. It can be, and is a problem for me. Just the nature of running a car with higher miles. Every 10k miles, I need to add a half bottle of SC fluid. Every 10k miles or so, I need to add a little coolant. It leaks a little from somewhere. Am I that concerned that I am going to tear down my motor and try to find it? Nope, it doesn't leak that much. But it does leak enough that it would cause a problem if I ran Dex Cool.

Additionally, it is basically impossible to have a cooling system without air touching coolant somewhere. Even look in your overflow tank? That's right, air. So Dex Cool may work fine. But in most systems, with increasing miles, the cooling system will start to see air. If you are running a non-Dex Cool coolant, these small leaks that are not important enough to fix don't cause a problem. But in systems that do run dex cool, these leaks are highly detrimental to the cooling system, as well and the entire engine.

Well said Zef.

And lets not forget the cavitation that may be present in areas like the water pump.