The relationship I have read up on was due to oxygen exposure causing sludge of dexcool. I had a universal antifreeze at 100k, mechanics choice.
How do you prevent oxygen from comming in contact with the coolant? Impossible in the overflow tank,and in the radiator, I guess a better chance.
Maybe you can explain more fully what “oxygen exposure” consists of and how it happens and how to avoid it.
What I notice is with “normal green” there is no sludge formed,either with or without oxygen exposure. DexCool did not appear to be a change for the better.
My son used to have perpetual Dex Cool sludging problems, along with 2 premature water pump failures, and no amount of flushing or bleeding would cure it.
Flush it thoroughly, bleed it thoroughly, and 6 months later it would look like swamp mud again.
Since a cooling system must have some air space in it for expanion purposes I don’t know how one rids the system of oxygen.
I converted my son’s car to green coolant about 6 years ago after the second water pump failure and it’s stayed perfectly clean with no sludging or pump failures ever since.
Dex Cool was an aggravation and green is pretty much pour and forget so why put up with the aggravation.
"One of the problems associated with Dex-Cool? happens when air or oxygen enters the cooling system. When this happens, the air reacts with chemicals to create a heavy brown sludge which can clog up the system causing problems. The heat of the engine is the catalyst that causes this to happen."
google dex cool sludge oxygen and take your pick of sources. I found it credible enough to believe.
What I am getting at is that it is normal for air/oxygen to be in contact with the coolant (see post from OK 4450 below) Are you saying the owners are partially at fault in the DexCool situation? If the enginners did not take into account the very high likelyhood of oxygen comming into contact with the coolant,we have a design error/omission.
It seems from my reviews that a bad radiator cap can cause the problem, It is not air and fluid but air fluid and engine heat. There are so many cases of sludge formation or no problem that another unconsidered factor is a contributing factor. Somehow air introduced into the system is the reason for the problem.
What the…
"air fluid "
Can you explain that concept for us?
In any event, the GM cooling systems with which I am familiar are not closed systems and as a result, the coolant will come into contact with air in the non-pressurized overflow tank. Certainly the use of DexCool must count as one of GM’s bigger design goofs.
I gave my best guess backed up by web info, what is your explanation for some cars sludgeing at 30k and others at 110k with no problems (did you google it?) see previous post for search
Clearly, the problem with DexCool must be a result of air reacting with the chemicals that comprise the coolant, possibly with the added catalyst of heat.
My question is…what is “air fluid”?
Some instances were a bad radiator cap, it seems to be a reaction of air heat and the fluid, and your explanation is?.. ok I forgot a comma sorry Air, fluid, and heat.
Waterboy, consider this. Are you going to fill the radiator to overflowing?
If not, you’re leaving air in the system.
If you do fill it to overflowing and reinstall the cap what is going to happen?
Coolant is going to expand from heat, it will be forced out past a good radiator cap, and into the non-pressurized overflow bottle.
This will settle due to gravity and as the radiator/cooling system cools and contracts some of the coolant in the overflow bottle, along with some air, will be pulled back into the radiator.
You’re NEVER going to get all of the air out of a cooling system. If you think I’m full of it then fill your own car’s radiator to overflowing, install a new cap, drive around for a couple of weeks, and then recheck your radiator.
Should still be overflowing, right?
Ah! A comma can result in a huge difference in the meaning of a sentence. I was concerned that there was a concept–“air fluid”–with which I was not familiar. Thank you for the clarification.
You don’t want to get put on the “grammar police” list do you?
Some people seem to get offended when their grammar is corrected,your point about a comma and the huge difference made when ommited is well made.
Yup! It sure does make a difference.
Lynne Truss is the author of Eats, Shoots, and Leaves, a book on the topic of how the lack of punctuation, or incorrect punctuation, can make a huge difference in the meaning of a sentence. The title of her book was drawn from something that she read describing the eating habits of the Giant Panda.
The author of the piece on the panda stated that this animal, “Eats, shoots, and leaves”. That description would be fine if the panda was a gun-toting animal that was in the habit of firing its gun and then leaving the scene of the crime. However, since the grammar-impaired writer was describing the animal’s feeding habits, and meant to state that the Giant Panda “eats shoots and leaves”, the meaning was changed in a very significant manner by the insertion of unwanted commas. In a similar fashion, “air, fluid, and heat” became “air fluid” in this thread–thus my confusion regarding a new concept of which I was unaware.
No, I don’t want to be considered to be one of the “grammar police”, but then again, as the old saying tells us–“You can take the teacher out of the classroom, but you can’t take the classroom out of the teacher”. I may be retired after a long career in education, but that doesn’t mean that I have stopped trying to provide a bit of needed education here and there. When someone communicates unclearly, perhaps that person does need a bit of help. After all, when he/she fills out a job application, if that application is…less than literate…it could hurt his/her chances for employment, and that is very important.
The separate canister for extra fluid does keep air out of the system. As I said earlier the answer I put out there was seemed the best answer to me after looking into the problem to make myself somewhat knowledgeable for my coolant change.
Let me know how the test goes.
For something additional to think about, ponder me this.
What about Dex Cool’s exposure to air during the manufacturing process?
What about the air that exists in the tops of the 55 gallon drums and in the tops of the 1 gallon jugs? Some of that is in place for months, and maybe even years.
I’ve actually been into a warehouse where antifreeze was stored (pallets of drums and cases of jugs) and date codes showed that much of it was 6 months to a year old.
Tell me why Dex Cool is not sludging up in the barrels and jugs as it sits on the shelf since oxygen is present during the entire time.
Sounds like a chemical composition/heat issue to me rather than an air related one.
ok4450,
I have a 2000 Camry and it stays at overflowing anytime I have removed the cap as does my 76 Vega as long as I maintain the overflow level in spec.
Have you had other results?
I’ve seen a lot of results.
Consider this one. Not a true overflow tank but will make a point since it’s a Dex Cool vehicle.
http://cgi.ebay.com/ebaymotors/99-00-01-CHEVY-CAVALIER-COOLANT-TANK-BOTTLE-RESERVOIR_W0QQcmdZViewItemQQ_trksidZp3286Q2em20Q2el1116QQitemZ310080142264QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
Those tanks have a MIN and a MAX mark on them with everything between MIN and the cap being oxygen. This allows for expanion of hot coolant. Fill it up to the brim and it’s simply going to get puked out and replaced by air.
My question still stands. If oxygen is behind the sludging then why is Dex Cool not sludging in the containers it’s delivered in?
Every single one of those containers not only has oxygen present but oxygen has also been present inside those containers for months and years.
I’ve had 3/4 of a jug of Dex Cool sitting in my basement for about 4 years now and it hasn’t sludged . How long does it take for the oxygen to start working?