Dex-cool or dex-poo?
I removed Death-cool from my Monte the 3rd day I owned it, I also removed it from my Trans Am. As I recall DC was better suited for a sealed system, our with the overflow tank is vented. I look at DC like a dog that has bit several people, it might be nice to you now, but don't turn your back. I also think most people who had problems were probably extending the maintenance service intervals, in combo with the sealed vs non sealded system. I've never had a problem with traditional green, and that is what I run in all my vehicles.
Joined: Apr 2010
Posts: 12,601
From: Mentor, Ohio
I know Dex Cool was offered as far back as some '94 vehicles. My friend's '94 Formula Firebird (currently has about 70K miles on it today and NO gasket work) runs Dex to this day. But he does flush the system periodically. No issues, and the original Dex that was in this car from the factory was the bad formula stuff.
Bottom line, if you are running a '00 or newer Dex vehicle, you have no reason to panic, that is the proper formula and no worse then the green stuff as far as being corrosive. If at the next regular fluid flush/change interval you want to switch to green as it helps you sleep better, that would be the time to do it.
Truth be told, I was tempted to switch off Dex to the green stuff so I don't have some cars in my fleet on Dex and others not (so I run ONE type of anti-freeze). But I have not made the switch and recently flushed the Monte last year and the Impala about a month ago.
@Scooby - All liquid cooled engines run as a "closed" system and all have a method of venting (otherwise, as the fluid heats and expands, if something was not available to vent the additional pressure, the system would explode). The overflow bottle design like it is is not issue. Coolant flows into it when the radiator cap reaches it's presure limit and opens up.
Bottom line, if you are running a '00 or newer Dex vehicle, you have no reason to panic, that is the proper formula and no worse then the green stuff as far as being corrosive. If at the next regular fluid flush/change interval you want to switch to green as it helps you sleep better, that would be the time to do it.
Truth be told, I was tempted to switch off Dex to the green stuff so I don't have some cars in my fleet on Dex and others not (so I run ONE type of anti-freeze). But I have not made the switch and recently flushed the Monte last year and the Impala about a month ago.
@Scooby - All liquid cooled engines run as a "closed" system and all have a method of venting (otherwise, as the fluid heats and expands, if something was not available to vent the additional pressure, the system would explode). The overflow bottle design like it is is not issue. Coolant flows into it when the radiator cap reaches it's presure limit and opens up.
Honestly dex-cool did receive a bad rap, but the problem was mostly (in my opinion) due to the change intervals that were written in the owner's manual and under the hood. Most people never changed their fluids or check them because dex-cool is SUPPOSED to last 5 years or 100,000 miles.
However, if you start to get a little low on fluid, in a cast iron engine (which we have) rust WILL form. Then the coolant will mix with this rust and create some of the dark red that we are used to seeing. So if you don't keep an eye on your levels, or pop the radiator cap, or keep the system bled properly, etc. etc. You can start to get low and cause this rust.
Dex-Cool exists because of the use of 2-EHA which helps if you are using hard water in the 50/50 mix since America has so much hard water. It is supposed to HELP with this rusting problem, but if you are low it can't do everything for you.
However, that same 2-EHA is what is known to do damage to gaskets because it is considered a plasticizer (which just means that it softens plastic). However, just softening plastic doesn't ruin everything, if you soften it and overheat it because you are low on fluid probably did the most harm.
Green fluid doesn't have anything to really help with cast iron (mostly for aluminum), and it gets worse in hard water, so that's why I keep the Dex in my engine. I just turned the flushing procedure in half and try to keep it flushed every other year. This way I can keep an eye on the levels a lot better.
Hopefully this post helps clear up the research that I have done in my thought process of whether I should switch my car to green.
However, if you start to get a little low on fluid, in a cast iron engine (which we have) rust WILL form. Then the coolant will mix with this rust and create some of the dark red that we are used to seeing. So if you don't keep an eye on your levels, or pop the radiator cap, or keep the system bled properly, etc. etc. You can start to get low and cause this rust.
Dex-Cool exists because of the use of 2-EHA which helps if you are using hard water in the 50/50 mix since America has so much hard water. It is supposed to HELP with this rusting problem, but if you are low it can't do everything for you.
However, that same 2-EHA is what is known to do damage to gaskets because it is considered a plasticizer (which just means that it softens plastic). However, just softening plastic doesn't ruin everything, if you soften it and overheat it because you are low on fluid probably did the most harm.
Green fluid doesn't have anything to really help with cast iron (mostly for aluminum), and it gets worse in hard water, so that's why I keep the Dex in my engine. I just turned the flushing procedure in half and try to keep it flushed every other year. This way I can keep an eye on the levels a lot better.
Hopefully this post helps clear up the research that I have done in my thought process of whether I should switch my car to green.
I replaced the intake gaskets on my 02 gran prix 2 years ago for mainly piece of mind...thought the 3.8l was bullet-proof. The original gasket was just starting to break down a bit @116kms....that was 2 yrs ago....refilled with dexcool and no scum so far. The guy that works on my cars is GM tech and said not to use prestone or green anti freeze as it will etch the metal.....after 12 yrs of service from him i tend to trust him
According to the previous owner. My 02 Monte Carlo LS had the intake manifold gasket replaced at 50k miles. I guess coolant was disappearing and it turned out to the be the intake manifold gasket. I hope it didn't do much damage as I guess the coolant was going in the oil. It's got 85k miles on it now.
@Scooby - All liquid cooled engines run as a "closed" system and all have a method of venting (otherwise, as the fluid heats and expands, if something was not available to vent the additional pressure, the system would explode). The overflow bottle design like it is is not issue. Coolant flows into it when the radiator cap reaches it's presure limit and opens up.
Consumer complaints about DexCool in GM Engines
Changing Dex-Cool @ 5 Years 63,000 KM - Page 1
From the above link:
GM makes/made 2 mistakes with Dexcool, they used incompatible gaskets with it in certain V-6 engines because they we're to cheap to spend 10c more on the proper gasket materials, then they refused to redesign the cooling systems from an open to a closed system. DEXCOOL doesn't play well with air, it reacts with it to form even stronger acids, with then allows it to eat through certain gasket materials. On those engines designed from day one to use DEXCOOL, their has been no issues with it. Both Ford and Dodge have used it and Ford is once again now using DEXCOOL in their engines. Regadless, coolant should be changed every couple of years, regardless of type, all types break down and turn acidic with time.
Joined: Apr 2010
Posts: 12,601
From: Mentor, Ohio
I can tell ya, I've seen plenty of nylon intake gaskets go bad running nothing but the good ol' green stuff from day one. IMO, the gasket failure is linked to the fact they used nylon, which cannot with stand hot fluid pounding on it.
Now FelPro makes aluminum carrier gaskets, which is what GM should have had to begin with.
To each there own. All I'm saying is I don't feel today's formula of Dex is a problem. Perhaps the old formula was. But I think flushing the system regularly (as even recommended with the green stuff) will ensure safe use of the cooling system. This is something some people tend to neglect.
Now FelPro makes aluminum carrier gaskets, which is what GM should have had to begin with.
To each there own. All I'm saying is I don't feel today's formula of Dex is a problem. Perhaps the old formula was. But I think flushing the system regularly (as even recommended with the green stuff) will ensure safe use of the cooling system. This is something some people tend to neglect.
Mine has been flushed at least three or four times, finally a professional job by the last radiator shop in the area held it over for a few years. Just had a leak fixed in the radiator and was told it needs a flush again. Goody. Sunk at least $1,000 into that radiator I think.
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