Dex-Cool, what's the real story
04-21-2009, 10:47 AM
#1
Dex-Cool, what's the real story
Has anyone had any problems with the orange long-life coolant in their 928. I put some Prestone Dex-Cool rated antifreeze in on my last drain and fill two years ago. I think it was recommended on Devek's website (RIP). Anyway, I've been reading some horror stories about Dex-Cool on the web. They mostly seem like plaintiff's lawyer's BS, but they have me a little scared.
Has anyone exerienced any problems from the orange stuff in their 928. I'll probably change it out to be safe, but do I have anything to really worry about. Also, on my last coolant drain one of my block plugs was pretty stuck, so I just left it in and drained the other side. Any safe way to try and remove. Thanks,
Steve
'89 S4 Auto
Has anyone exerienced any problems from the orange stuff in their 928. I'll probably change it out to be safe, but do I have anything to really worry about. Also, on my last coolant drain one of my block plugs was pretty stuck, so I just left it in and drained the other side. Any safe way to try and remove. Thanks,
Steve
'89 S4 Auto
04-21-2009, 11:04 AM
#4
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The primary problem with DexCool seems to be that it doesn't like air. If used in a "sealed" system, where there is no air in the engine or radiator, it works well. If the coolant level gets low, allowing air into the cooling system, the DexCool can gel or cause radiator plugging.
Given the potential problems, I do not use it in my 928s. At the moment, I am using one of the European OAT-based coolants.
Given the potential problems, I do not use it in my 928s. At the moment, I am using one of the European OAT-based coolants.
04-21-2009, 11:07 AM
#5
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The orange stuff seems to be compatible with our engines. The thing I don't like about the Dex-Cool is that it seems to seap out very easily. That said it generally is not recommended for our cars.
There is ONE coolant commercially available that is recommended and does not promote corosion of the aluminum in the heads. Zerex G-05 is what I and sveral other use exclusivly in the 928. You may have to call around as I know you cannot get it at Autozone or Advanced auto parts. I get mine here in Michigan from Murray's autp parts (now O'Riley so who knows if they will continue to carry it).
As for the block drains, I don't know what to tell you. You could try some heat around the area, but it'll be tough with coolant in the engine to make a real difference. Just be sure to flush your engine really well with water before you try and swap to the G-05.
There is ONE coolant commercially available that is recommended and does not promote corosion of the aluminum in the heads. Zerex G-05 is what I and sveral other use exclusivly in the 928. You may have to call around as I know you cannot get it at Autozone or Advanced auto parts. I get mine here in Michigan from Murray's autp parts (now O'Riley so who knows if they will continue to carry it).
As for the block drains, I don't know what to tell you. You could try some heat around the area, but it'll be tough with coolant in the engine to make a real difference. Just be sure to flush your engine really well with water before you try and swap to the G-05.
04-21-2009, 11:15 AM
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I used Dex-Cool in my '89 for two years. It left a lot of orange crumbly stuff in the thermostat housing. All the other coolants leave some buildup in various places but the Dex-Cool looks like it leaves 5x as much.
Didn't we figure out two coolant threads ago that the G-05 is the same stuff as the Prestone LL? Both OAT-based? Or if not, both so substantially similar that the differences were hardly objective?
Didn't we figure out two coolant threads ago that the G-05 is the same stuff as the Prestone LL? Both OAT-based? Or if not, both so substantially similar that the differences were hardly objective?
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04-21-2009, 11:20 AM
#8
Coolant
Now I'm confused, and I apologize for not checking past coolant threads. I've got Prestone LL (silver colored bottle) in my car, but it's orange and says Dex-Cool in big letters on it. Is this stuff bad or OK.
I'm going to change it to be safe anyway, butr appreciate any advice. Thanks.
Steve
'89 S4 Auto
I'm going to change it to be safe anyway, butr appreciate any advice. Thanks.
Steve
'89 S4 Auto
04-21-2009, 11:22 AM
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I have used Dex Cool for 10 years in several cars and never had a problem.
I wonder which transfers heat better, the OAT coolants or Dex Cool.
04-21-2009, 11:24 AM
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04-21-2009, 11:26 AM
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04-21-2009, 11:27 AM
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I was correct. Here is the FAQ from Prestone's website:
Q. Does Prestone® Antifreeze/Coolant contain phosphates?
A. Some European automobile manufacturers request that a phosphate-free antifreeze be used in their vehicles. This issue is related to the extremely high mineral content of the water in Europe. If you were to mix an antifreeze that contained phosphates with the type of water they have in Europe, it may produce deposits that can settle in the cooling system and promote corrosion. However, in North America we do not have this type of water problem. Typical North American coolants have contained phosphates (which is part of the corrosion inhibitor package) for many years. Therefore, the question of phosphates is a non-issue here in North America. Prestone® Antifreeze/Coolant is completely safe for use in both foreign and domestic vehicles. For those consumers who would feel more comfortable using a phosphate-free antifreeze, our Prestone® Extended Life 5/150 Antifreeze/Coolant is phosphate, silicate, and borate free. This coolant uses a special chemistry and technology that extends the life of the corrosion inhibitor package so that it lasts for five years or 150,000 miles (whichever comes first), and is safe for all cars and light trucks (old or new). Prestone® Extended Life 5/150 Antifreeze/Coolant has been approved by General Motors under their DEX-COOL® specifications and is compatible with other DEX-COOL® approved coolants.
A. Some European automobile manufacturers request that a phosphate-free antifreeze be used in their vehicles. This issue is related to the extremely high mineral content of the water in Europe. If you were to mix an antifreeze that contained phosphates with the type of water they have in Europe, it may produce deposits that can settle in the cooling system and promote corrosion. However, in North America we do not have this type of water problem. Typical North American coolants have contained phosphates (which is part of the corrosion inhibitor package) for many years. Therefore, the question of phosphates is a non-issue here in North America. Prestone® Antifreeze/Coolant is completely safe for use in both foreign and domestic vehicles. For those consumers who would feel more comfortable using a phosphate-free antifreeze, our Prestone® Extended Life 5/150 Antifreeze/Coolant is phosphate, silicate, and borate free. This coolant uses a special chemistry and technology that extends the life of the corrosion inhibitor package so that it lasts for five years or 150,000 miles (whichever comes first), and is safe for all cars and light trucks (old or new). Prestone® Extended Life 5/150 Antifreeze/Coolant has been approved by General Motors under their DEX-COOL® specifications and is compatible with other DEX-COOL® approved coolants.
04-21-2009, 11:30 AM
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04-21-2009, 11:31 AM
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