green coolant
- Thread starter wadedog
- Start date
- Status
Check your owner's manual to be sure, but I'd imagine you do want the traditional green formula.
Kestas
Staff member
I have the impression that Dex-Cool is used only on systems where the pressurized cap is on the overflow tank. Dex-Cool doesn't like to mix with a lot of air.
I don't see whay you can't use Zerex G-05 in place of the traditional green.
I don't see whay you can't use Zerex G-05 in place of the traditional green.
I would personally use traditional green (as i did in my 85 monte ss) or one of the universal coolants.
Where did you get the idea that traditional radiators with pressure caps inevitably trap air? Once the air is purged, and assuming there's a non-pressurized overflow bottle and no leaks from compromised hoses or seals, the sealed system will remain air-free unless evaporation drops the coolant level sufficiently to allow air to be drawn in. However, the same could eventually happen in systems with pressurized overflow bottles, too. (You can always tell which car owners don't bother checking their coolant level routinely - they're the frustrated motorists standing by the side of the road with their cars' hoods propped up after the weather turns hot.)
Kestas
Staff member
Correct me if I'm wrong.
I was under the impression that coolant often travels to and from the overflow tank during thermal cycling. Whenever I service a cooling system, the overflow level keeps dropping every morning until all air is burped from the system. All this back-and-forth of coolant to and from the overflow exposes it to ambient air, and this is what Dex-Cool doesn't like. With pressurized overflow tanks, coolant only mixes with the smaller volume of air trapped in the overflow tank during this cycling.
Again, this is the impression I have of the problem. I believe the reports I've read with Dex-Cool problems include those people that have a leaky system, or a system that draws superfluous air into the charge, and that keeping a system "tight" to exclude air will reduce the chance of having problems with Dex-Cool.
I was under the impression that coolant often travels to and from the overflow tank during thermal cycling. Whenever I service a cooling system, the overflow level keeps dropping every morning until all air is burped from the system. All this back-and-forth of coolant to and from the overflow exposes it to ambient air, and this is what Dex-Cool doesn't like. With pressurized overflow tanks, coolant only mixes with the smaller volume of air trapped in the overflow tank during this cycling.
Again, this is the impression I have of the problem. I believe the reports I've read with Dex-Cool problems include those people that have a leaky system, or a system that draws superfluous air into the charge, and that keeping a system "tight" to exclude air will reduce the chance of having problems with Dex-Cool.
The problem is not ambient air contacting Dexcool. It is coolant low enough that the metal parts inside the cooling system is exposed to air, especially over a long period of time.
Kestas
Staff member
This link has an article written in 2000 on the Dex-Cool "problem".
http://www.imcool.com/articles/antifreeze-coolant/CPM-52-DEXArticle-Excerpt.pdf
It pretty much mirrors what you say, about the problem presenting itself when the coolant level gets too low. Beyond that, it doesn't address the technical mechanism of coolant turning to gel. I'm guessing the coolant gets locally overheated, causing it to gel.
We have decades of experience with the old green coolant. Lots of people have let coolant levels get too low, yet the green coolant has never been known to gel under these conditions. Therein lies the problem with Dex-Cool.
http://www.imcool.com/articles/antifreeze-coolant/CPM-52-DEXArticle-Excerpt.pdf
It pretty much mirrors what you say, about the problem presenting itself when the coolant level gets too low. Beyond that, it doesn't address the technical mechanism of coolant turning to gel. I'm guessing the coolant gets locally overheated, causing it to gel.
We have decades of experience with the old green coolant. Lots of people have let coolant levels get too low, yet the green coolant has never been known to gel under these conditions. Therein lies the problem with Dex-Cool.
The old chemistry "green snot of death" green coolant did indeed gel up when the silicate fell out of suspension. It left a gunky mess behind.
Kestas
Staff member
Then why are people all of a sudden excited about Dex-Cool gelling in their cooling systems?
Much of the problem with DEX-COOL was GM's leak-prone V type engines. Their plastic intake manifolds, which also carried coolant to aid quick warmup, had a much lower rate of thermal expansion than the aluminum cylinder heads so leaks were almost inevitable anytime after 30,000 miles and up. Once air had a convenient path into the coolant, the results were predictable. Big Jim is right - the old green-snot-o'-death coolants with high silicate levels were susceptible to silicates falling out of suspension as a nasty glop. (Even unused in a sealed jug, this stuff only had a shelf life of 2-3 years. DEX-COOL, on the other hand, has a listed shelf life of eight years though its closer to indefinite.) Newer versions of conventional antifreeze have much better stability due to considerably reduced levels of silicates - with apparently no reduction in corrosion protection. But air in DEX-COOL leads to an entirely different gel chemistry - and the results ain't perty fer the engine. Keep air out of DEX-COOL, though, in a properly designed and functioning cooling system and the long term results are pristine. I also put over four years on a '96 Honda Accord with Havoline DEX-COOL without any regrets. Running DEX-COOL in a leak-prone cooling system is somewhat analagous to the poor slob who religiously downs a 325 mg aspirin tablet each day but packs in 3,000 calories of saturated fat, too - and then blames the aspirin for his eventual heart attack.
(On a side note, everything you pointed out about the dynamics of a non-pressurized puke tank is correct. My point, though, was that if the car owner maintains a proper level in the puke tank, and has a leak-free pressure cooling system and radiator filler neck to puke tank hose, once the air is purged, there won't be an avenue for air to re-enter the pressure system. My Sonata V6 is a case in point. I've just entered year three with WalMart's SuperTech dexclone. It was ovefilled initially, but intervening time-related water evaportion has brought the level in the puke tank down to only about an inch and a half above the midline when cold. I've checked the puke tank weekly and the cold fill level at the radiator monthly. Nothing has had to be added since I drained the slightly murky conventional swill Hyundai installed in Korea.)
(On a side note, everything you pointed out about the dynamics of a non-pressurized puke tank is correct. My point, though, was that if the car owner maintains a proper level in the puke tank, and has a leak-free pressure cooling system and radiator filler neck to puke tank hose, once the air is purged, there won't be an avenue for air to re-enter the pressure system. My Sonata V6 is a case in point. I've just entered year three with WalMart's SuperTech dexclone. It was ovefilled initially, but intervening time-related water evaportion has brought the level in the puke tank down to only about an inch and a half above the midline when cold. I've checked the puke tank weekly and the cold fill level at the radiator monthly. Nothing has had to be added since I drained the slightly murky conventional swill Hyundai installed in Korea.)
Ditto with my G-05 in my Hyundai..
Good tip, Mr. Ray
.
Level hasn't budged in 20K and 9 months..
Good tip, Mr. Ray
Level hasn't budged in 20K and 9 months..
- Status
