Black Sludge in Coolant
08-07-2017, 12:56 PM
#21
Safety Car
What type of anti freeze are you using?
Hello There,
I had a problem with an engine where the anti-freeze turned blackish and was greasy to the feel. It was in a 2005 Buick 3.5 liter V-6 that had been running the original DEXCOOL for close to 90,000 miles. The car was acting up and the cooling fans had not been working properly. It had overheated three times in the last 100 miles on the engine. It was finally enough to warp one of my cylinder heads.
When I opened the radiator cap (while it was still on the road) it was covered in a material like black sludge. I also found a good deal of it in the Overflow bottle as well. There was a high level mark where it had a ring of black stuff in the overflow bottle. When I opened the radiator cap while the engine was running it would have bubbles in it along with floating material that looked like black sludge.
I have been building and maintaining Solar Thermal systems a good deal of my life. In the solar industry we commonly use propylene glycol as our antifreeze to protect the copper pipes and the collectors. I saw with my own eyes a five gallon bucket between one third and half-full of black paste that had been the copper pipes before.
Knowing that DEXCOOL was made using Propylene Glycol as one of the prime ingredients I became suspicious. You probably eat or drink propylene glycol almost daily if not more often. It is commonly used in soft drinks and milk shakes and a multitude of other products.
In solar systems where they operate at a higher temperature (250-350 degrees F) we have seen the propylene glycol break down and turn blackish. When the propylene glycol breaks down it turns into an acidic mess that will dissolve copper used in our solar systems.
This is based on a real life experience not some theoretical mumbo jumbo.
I am sure I will get nailed for even suggesting this as I have been in the past by certain members of this forum.
Before you tear apart your motor try flushing hot water through the system. Really clean your cars cooling system out well and try using some new anti-freeze and see if the trouble persists. I hate to see anybody tear a motor apart unnecessarily.
I ended up having to rebuild my Buick motor and I found that the "something" had eaten away and dissolved parts of my head gaskets and other gaskets exposed to the coolant. I would assume that some of the black junk I found floating in my system were pieces of gaskets that had been attacked by an overly acidic coolant.
There are Forum members armed with photographs of radiators cut up to allow viewing of the passageways that appear as almost "new" after 200,000 miles and more of usage with Dexcool as its anti-freeze. If Dexcool is used properly and never exposed to higher than normal temperatures it is a great anti-freeze as millions of cars are using it everyday.
After my experience I have stopped using Dexcool in ALL of my 7 cars.
I am using the old green Ethylene Glycol type coolants in my tiny fleet and in my boat. I am also very picky about the mixtures I use in my performance cars. I live in Virginia and we are in a more southerly area where it does not get as cold as other parts of this country. The coldest I have ever seen here was -5 degrees F. I use a 70% distilled water, 30% anti-freeze which gives me all the protection I will need down here in Virginia. I flush the entire system and replace the coolant and the 16 lb.radiator cap every five years for my peace of mind.
Anti-freeze does not cool as well as water does. The standard 50% anti freeze is for "protection" as they don't know where the car will end up being used. Use as little anti-freeze as is needed in your part of the country. I don't take my Corvette north during the colder months and it has never needed any more freeze protection.
I hope that you have success in finding a quick solution to your issues and that you will not have to tear apart the engine! Good Luck!
I had a problem with an engine where the anti-freeze turned blackish and was greasy to the feel. It was in a 2005 Buick 3.5 liter V-6 that had been running the original DEXCOOL for close to 90,000 miles. The car was acting up and the cooling fans had not been working properly. It had overheated three times in the last 100 miles on the engine. It was finally enough to warp one of my cylinder heads.
When I opened the radiator cap (while it was still on the road) it was covered in a material like black sludge. I also found a good deal of it in the Overflow bottle as well. There was a high level mark where it had a ring of black stuff in the overflow bottle. When I opened the radiator cap while the engine was running it would have bubbles in it along with floating material that looked like black sludge.
I have been building and maintaining Solar Thermal systems a good deal of my life. In the solar industry we commonly use propylene glycol as our antifreeze to protect the copper pipes and the collectors. I saw with my own eyes a five gallon bucket between one third and half-full of black paste that had been the copper pipes before.
Knowing that DEXCOOL was made using Propylene Glycol as one of the prime ingredients I became suspicious. You probably eat or drink propylene glycol almost daily if not more often. It is commonly used in soft drinks and milk shakes and a multitude of other products.
In solar systems where they operate at a higher temperature (250-350 degrees F) we have seen the propylene glycol break down and turn blackish. When the propylene glycol breaks down it turns into an acidic mess that will dissolve copper used in our solar systems.
This is based on a real life experience not some theoretical mumbo jumbo.
I am sure I will get nailed for even suggesting this as I have been in the past by certain members of this forum.
Before you tear apart your motor try flushing hot water through the system. Really clean your cars cooling system out well and try using some new anti-freeze and see if the trouble persists. I hate to see anybody tear a motor apart unnecessarily.
I ended up having to rebuild my Buick motor and I found that the "something" had eaten away and dissolved parts of my head gaskets and other gaskets exposed to the coolant. I would assume that some of the black junk I found floating in my system were pieces of gaskets that had been attacked by an overly acidic coolant.
There are Forum members armed with photographs of radiators cut up to allow viewing of the passageways that appear as almost "new" after 200,000 miles and more of usage with Dexcool as its anti-freeze. If Dexcool is used properly and never exposed to higher than normal temperatures it is a great anti-freeze as millions of cars are using it everyday.
After my experience I have stopped using Dexcool in ALL of my 7 cars.
I am using the old green Ethylene Glycol type coolants in my tiny fleet and in my boat. I am also very picky about the mixtures I use in my performance cars. I live in Virginia and we are in a more southerly area where it does not get as cold as other parts of this country. The coldest I have ever seen here was -5 degrees F. I use a 70% distilled water, 30% anti-freeze which gives me all the protection I will need down here in Virginia. I flush the entire system and replace the coolant and the 16 lb.radiator cap every five years for my peace of mind.
Anti-freeze does not cool as well as water does. The standard 50% anti freeze is for "protection" as they don't know where the car will end up being used. Use as little anti-freeze as is needed in your part of the country. I don't take my Corvette north during the colder months and it has never needed any more freeze protection.
I hope that you have success in finding a quick solution to your issues and that you will not have to tear apart the engine! Good Luck!
The following users liked this post:
Bfenty (08-07-2017)
08-07-2017, 03:50 PM
#22
Pro
Hello There,
I had a problem with an engine where the anti-freeze turned blackish and was greasy to the feel. It was in a 2005 Buick 3.5 liter V-6 that had been running the original DEXCOOL for close to 90,000 miles. The car was acting up and the cooling fans had not been working properly. It had overheated three times in the last 100 miles on the engine. It was finally enough to warp one of my cylinder heads.
When I opened the radiator cap (while it was still on the road) it was covered in a material like black sludge. I also found a good deal of it in the Overflow bottle as well. There was a high level mark where it had a ring of black stuff in the overflow bottle. When I opened the radiator cap while the engine was running it would have bubbles in it along with floating material that looked like black sludge.
I have been building and maintaining Solar Thermal systems a good deal of my life. In the solar industry we commonly use propylene glycol as our antifreeze to protect the copper pipes and the collectors. I saw with my own eyes a five gallon bucket between one third and half-full of black paste that had been the copper pipes before.
Knowing that DEXCOOL was made using Propylene Glycol as one of the prime ingredients I became suspicious. You probably eat or drink propylene glycol almost daily if not more often. It is commonly used in soft drinks and milk shakes and a multitude of other products.
In solar systems where they operate at a higher temperature (250-350 degrees F) we have seen the propylene glycol break down and turn blackish. When the propylene glycol breaks down it turns into an acidic mess that will dissolve copper used in our solar systems.
This is based on a real life experience not some theoretical mumbo jumbo.
I am sure I will get nailed for even suggesting this as I have been in the past by certain members of this forum.
Before you tear apart your motor try flushing hot water through the system. Really clean your cars cooling system out well and try using some new anti-freeze and see if the trouble persists. I hate to see anybody tear a motor apart unnecessarily.
I ended up having to rebuild my Buick motor and I found that the "something" had eaten away and dissolved parts of my head gaskets and other gaskets exposed to the coolant. I would assume that some of the black junk I found floating in my system were pieces of gaskets that had been attacked by an overly acidic coolant.
There are Forum members armed with photographs of radiators cut up to allow viewing of the passageways that appear as almost "new" after 200,000 miles and more of usage with Dexcool as its anti-freeze. If Dexcool is used properly and never exposed to higher than normal temperatures it is a great anti-freeze as millions of cars are using it everyday.
After my experience I have stopped using Dexcool in ALL of my 7 cars.
I am using the old green Ethylene Glycol type coolants in my tiny fleet and in my boat. I am also very picky about the mixtures I use in my performance cars. I live in Virginia and we are in a more southerly area where it does not get as cold as other parts of this country. The coldest I have ever seen here was -5 degrees F. I use a 70% distilled water, 30% anti-freeze which gives me all the protection I will need down here in Virginia. I flush the entire system and replace the coolant and the 16 lb.radiator cap every five years for my peace of mind.
Anti-freeze does not cool as well as water does. The standard 50% anti freeze is for "protection" as they don't know where the car will end up being used. Use as little anti-freeze as is needed in your part of the country. I don't take my Corvette north during the colder months and it has never needed any more freeze protection.
I hope that you have success in finding a quick solution to your issues and that you will not have to tear apart the engine! Good Luck!
I had a problem with an engine where the anti-freeze turned blackish and was greasy to the feel. It was in a 2005 Buick 3.5 liter V-6 that had been running the original DEXCOOL for close to 90,000 miles. The car was acting up and the cooling fans had not been working properly. It had overheated three times in the last 100 miles on the engine. It was finally enough to warp one of my cylinder heads.
When I opened the radiator cap (while it was still on the road) it was covered in a material like black sludge. I also found a good deal of it in the Overflow bottle as well. There was a high level mark where it had a ring of black stuff in the overflow bottle. When I opened the radiator cap while the engine was running it would have bubbles in it along with floating material that looked like black sludge.
I have been building and maintaining Solar Thermal systems a good deal of my life. In the solar industry we commonly use propylene glycol as our antifreeze to protect the copper pipes and the collectors. I saw with my own eyes a five gallon bucket between one third and half-full of black paste that had been the copper pipes before.
Knowing that DEXCOOL was made using Propylene Glycol as one of the prime ingredients I became suspicious. You probably eat or drink propylene glycol almost daily if not more often. It is commonly used in soft drinks and milk shakes and a multitude of other products.
In solar systems where they operate at a higher temperature (250-350 degrees F) we have seen the propylene glycol break down and turn blackish. When the propylene glycol breaks down it turns into an acidic mess that will dissolve copper used in our solar systems.
This is based on a real life experience not some theoretical mumbo jumbo.
I am sure I will get nailed for even suggesting this as I have been in the past by certain members of this forum.
Before you tear apart your motor try flushing hot water through the system. Really clean your cars cooling system out well and try using some new anti-freeze and see if the trouble persists. I hate to see anybody tear a motor apart unnecessarily.
I ended up having to rebuild my Buick motor and I found that the "something" had eaten away and dissolved parts of my head gaskets and other gaskets exposed to the coolant. I would assume that some of the black junk I found floating in my system were pieces of gaskets that had been attacked by an overly acidic coolant.
There are Forum members armed with photographs of radiators cut up to allow viewing of the passageways that appear as almost "new" after 200,000 miles and more of usage with Dexcool as its anti-freeze. If Dexcool is used properly and never exposed to higher than normal temperatures it is a great anti-freeze as millions of cars are using it everyday.
After my experience I have stopped using Dexcool in ALL of my 7 cars.
I am using the old green Ethylene Glycol type coolants in my tiny fleet and in my boat. I am also very picky about the mixtures I use in my performance cars. I live in Virginia and we are in a more southerly area where it does not get as cold as other parts of this country. The coldest I have ever seen here was -5 degrees F. I use a 70% distilled water, 30% anti-freeze which gives me all the protection I will need down here in Virginia. I flush the entire system and replace the coolant and the 16 lb.radiator cap every five years for my peace of mind.
Anti-freeze does not cool as well as water does. The standard 50% anti freeze is for "protection" as they don't know where the car will end up being used. Use as little anti-freeze as is needed in your part of the country. I don't take my Corvette north during the colder months and it has never needed any more freeze protection.
I hope that you have success in finding a quick solution to your issues and that you will not have to tear apart the engine! Good Luck!
First Dex-Cool is not a Propylene Glycol based coolant. It is an OAT based Ethylene Glycol coolant dyed bright orange and licensed by GM. One of the potential problems with Dex-Cool is that it contains a known plasticizer, 2-ethylhexanoic acid (2-EHA), in it's corrosion inhibitor package. That means some cooling system components and seals may eventually fail after prolonged contact with Dex-Cool. The end tanks found in all C4 radiators are made of plastic and may weaken and eventually fail with prolonged contact to Dex-Cool and it's clones. Dex-Cool has also eaten away some OEM GM cooling system gaskets and seals that apparently are not compatible with it! Other cooling system components may or may not be compatible with OAT type Dex-Cool. That may be the source of the black sludge the OP found in his coolant... He didn't say what type coolant he was running.
As for Propylene Glycol coolant, I wouldn't use it a C4 as your C4 cooling system was never designed to run it and it most likely isn't compatible with the seals and components found in a C4. Also note every C4 made except for the '96 model year wasn't spec'd by GM to run Dex-Cool either, so like a Propylene Glycol coolant I would choose not to run it as well!
08-07-2017, 04:25 PM
#23
Melting Slicks
That said, I ran the car for about a minute from cold, not enough to even get the engine hot, and I then popped the radiator cap off. There was a slight hiss of air, like it was under pressure. This points to exhaust gasses getting into the cooling system-that would be a sign of a head gasket issue.
If the compression tests good and your fluids are not going missing, I say just drive it and keep an eye on things. Also I would continue wiping that black stuff out of the cap/surge tank area until it mostly goes away. Of course keep an eye on the coolant level. Top off coolant from the overflow tank, the system is designed to pull in whatever amount is needed when the engine cools (self-burping).
08-07-2017, 04:42 PM
#24
Drifting
Thread Starter
Member Since: Mar 2017
Location: Nashville TN
Posts: 1,897
Received 164 Likes
on
136 Posts
2017 C4 of Year Finalist
I have learned that lesson a few years ago now. Never doing THAT again.
Thanks for the advice. That's my plan at this point. For now I will be babying it a little though, just until I see what happens.
I was actually just running straight water after the flush.The plan was always to drain it and do a proper mixture before the end of summer, but there was a decent amount of rust in the coolant before (from the car sitting so long), so I wanted to drain it once more before adding antifreeze, which costs a lot more than water! 
Now I'm running the green generic stuff-that's what I want, right?
If the compression tests good and your fluids are not going missing, I say just drive it and keep an eye on things. Also I would continue wiping that black stuff out of the cap/surge tank area until it mostly goes away. Of course keep an eye on the coolant level. Top off coolant from the overflow tank, the system is designed to pull in whatever amount is needed when the engine cools (self-burping).
That may be the source of the black sludge the OP found in his coolant... He didn't say what type coolant he was running.
Now I'm running the green generic stuff-that's what I want, right?
08-07-2017, 04:55 PM
#25
Melting Slicks
I was actually just running straight water after the flush.The plan was always to drain it and do a proper mixture before the end of summer, but there was a decent amount of rust in the coolant before (from the car sitting so long), so I wanted to drain it once more before adding antifreeze, which costs a lot more than water!
Now I'm running the green generic stuff-that's what I want, right?
Now I'm running the green generic stuff-that's what I want, right?
The following users liked this post:
Bfenty (08-07-2017)
08-07-2017, 05:05 PM
#26
Pro
I have learned that lesson a few years ago now. Never doing THAT again.
Thanks for the advice. That's my plan at this point. For now I will be babying it a little though, just until I see what happens.
I was actually just running straight water after the flush.The plan was always to drain it and do a proper mixture before the end of summer, but there was a decent amount of rust in the coolant before (from the car sitting so long), so I wanted to drain it once more before adding antifreeze, which costs a lot more than water!
Now I'm running the green generic stuff-that's what I want, right?
Thanks for the advice. That's my plan at this point. For now I will be babying it a little though, just until I see what happens.
I was actually just running straight water after the flush.The plan was always to drain it and do a proper mixture before the end of summer, but there was a decent amount of rust in the coolant before (from the car sitting so long), so I wanted to drain it once more before adding antifreeze, which costs a lot more than water!
Now I'm running the green generic stuff-that's what I want, right?
Do you know what was in it before you flushed it?
Did you remove the knock sensors or block drain plugs and the thermostat before your flush?
Do you know what's actually in the "generic green stuff" you are looking to use?
There are many, many coolant threads with excellent information in them on this forum. You should check them out before you proceed.
The following users liked this post:
Bfenty (08-07-2017)
08-07-2017, 08:19 PM
#27
Team Owner
Member Since: Dec 2012
Location: Outside the Quick Stop N.J.
Posts: 30,426
Received 1,596 Likes
on
1,074 Posts
What coolant exactly are you running now?
Do you know what was in it before you flushed it?
Did you remove the knock sensors or block drain plugs and the thermostat before your flush?
Do you know what's actually in the "generic green stuff" you are looking to use?
There are many, many coolant threads with excellent information in them on this forum. You should check them out before you proceed.
Do you know what was in it before you flushed it?
Did you remove the knock sensors or block drain plugs and the thermostat before your flush?
Do you know what's actually in the "generic green stuff" you are looking to use?
There are many, many coolant threads with excellent information in them on this forum. You should check them out before you proceed.
If you did not pull the knock sensors, you did not get a full flush of the system.
If not, do another flush, maybe even run just water for a day or two, then rinse and repeat. Don't overthink it, trust me, I know.
The following users liked this post:
Bfenty (08-07-2017)
08-07-2017, 10:10 PM
#29
1985 only has 1 knock sensor ,on the oppo side you will have a kc4 oil cooler nipple to pull or some kind of plug I suppose. If you dont get fluid what I had to do is use a coat hanger to clear the rust, I have cleared it 2x and now there isnt any last time I removed the hose.
08-08-2017, 07:44 AM
#33
Safety Car
Anti Freeze woes again
First let me say I would never recommend using Dex-Cool in any vehicle I own..... That being said let me correct some of the things you posted above;
First Dex-Cool is not a Propylene Glycol based coolant. It is an OAT based Ethylene Glycol coolant dyed bright orange and licensed by GM. One of the potential problems with Dex-Cool is that it contains a known plasticizer, 2-ethylhexanoic acid (2-EHA), in it's corrosion inhibitor package. That means some cooling system components and seals may eventually fail after prolonged contact with Dex-Cool. The end tanks found in all C4 radiators are made of plastic and may weaken and eventually fail with prolonged contact to Dex-Cool and it's clones. Dex-Cool has also eaten away some OEM GM cooling system gaskets and seals that apparently are not compatible with it! Other cooling system components may or may not be compatible with OAT type Dex-Cool. That may be the source of the black sludge the OP found in his coolant... He didn't say what type coolant he was running.
As for Propylene Glycol coolant, I wouldn't use it a C4 as your C4 cooling system was never designed to run it and it most likely isn't compatible with the seals and components found in a C4. Also note every C4 made except for the '96 model year wasn't spec'd by GM to run Dex-Cool either, so like a Propylene Glycol coolant I would choose not to run it as well!
First Dex-Cool is not a Propylene Glycol based coolant. It is an OAT based Ethylene Glycol coolant dyed bright orange and licensed by GM. One of the potential problems with Dex-Cool is that it contains a known plasticizer, 2-ethylhexanoic acid (2-EHA), in it's corrosion inhibitor package. That means some cooling system components and seals may eventually fail after prolonged contact with Dex-Cool. The end tanks found in all C4 radiators are made of plastic and may weaken and eventually fail with prolonged contact to Dex-Cool and it's clones. Dex-Cool has also eaten away some OEM GM cooling system gaskets and seals that apparently are not compatible with it! Other cooling system components may or may not be compatible with OAT type Dex-Cool. That may be the source of the black sludge the OP found in his coolant... He didn't say what type coolant he was running.
As for Propylene Glycol coolant, I wouldn't use it a C4 as your C4 cooling system was never designed to run it and it most likely isn't compatible with the seals and components found in a C4. Also note every C4 made except for the '96 model year wasn't spec'd by GM to run Dex-Cool either, so like a Propylene Glycol coolant I would choose not to run it as well!
One of the primary ingredients/agents of DEXCOOL is propylene glycol as shown below:
Primary agents
Methanol.
Ethylene glycol.
Propylene glycol.
Glycerol.
Maintenance
Traditional inhibitors.
Organic acid technology.
Hybrid organic acid technology.
Antifreeze - Wikipedia
https://en.wikipedia.org/wiki/Antifreeze
Lets agree on this ONE point. I would not use DEXCOOL in my lawnmower.
First, I am sorry if I was not clear, I said that "DEXCOOL was made using Propylene Glycol as one of the prime ingredients". Judging from the above chart I would assume that Propylene Glycol is in fact one of its prime ingredients, being #3 on the list.
Second, After my experience with the head gasket failure on my Buick I have been in touch with others dealing with this phenomenon. KNOWING that Propylene Glycol turns acid and can destroy metals like copper when it has seen overheating or overuse. Here below is a site that offers way more than I said to come to a similar point in the end.
This web site offers visual proof of what DEXCOOL can do to gaskets inside your engine.
http://www.zillamotorsports.com/DEX/
When DEXCOOL came out they advertised it as being a "Safe, non-toxic" anti-freeze. The initial anti freeze that came in my 2005 Buick was red, not orange or green.
Dexcool is listed as being good for FIVE years or up to 100,000 miles. Mine was nine years old but was treated by the Buick mechanics with some conditioners or additives.
"So it’s true that DexCool caused gasket leaks, but the real problem was incompatibility between the plastic and the coolant. Everyone assumes the problem was Dex-Cool, when in fact, the problem was the type of gasket material combined with the use of Dex-Cool. GM has redesigned the gaskets that the problem has now been fixed."
" Shops reported other problems with DexCool engines besides the 3.1 and 3.4-liter engine. Specifically, shops reported sludge buildup, especially in cast iron engines. But after a thorough investigation, it turns out that the only time sludge builds up is if the engine is low on coolant. When engines run low on coolant, the organic acid technologies oxidize and cause iron oxide deposits. The “rusting” usually NOT affect newer aluminum engines. But, running ANY engine when it’s low on organic acid type coolant cause form sludge."
Both of the preceding quotes are from this website:
http://ricksfreeautorepairadvice.com/is-dexcool-bad/
MAKO41 it seems that we are close in our thoughts regarding the use of DEXCOOL. With my personal experience with one of the main ingredients, I KNOW for a fact that propylene glycol does not belong in automobile engines.
I have been attacked personally for making statements against DEXCOOL on this site before. There is plenty of evidence that it works on some vehicles if it is replaced or replenished as necessary.
The more I read and learn about this red anti-freeze the less likely I would ever want to use it. They claim that GM has finally solved all the gasket issues and that all is well in the GM world.
Regarding the use of plain old propylene glycol for an anti-freeze in cars or even my C4. That would never happen as it is not designed for that kind of use.
I would use plain distilled water in my radiator (with a 16 lb cap on the radiator) before I will ever use DEXCOOL again.
I apologize if I have offended you by my choice of words. I was simply trying to show the OP that this might be a cause of what he was seeing in his engine IF he was using or had used DEXCOOL in his Corvette.
My goal here was to try to help other Corvette owners understand the pitfalls of using this anti-freeze. I am simply trying to help others!
Have a great day and may you remember to change the Ethylene Glycol based (GREEN) anti-freeze every two years as directed by the manufacturers.
The following users liked this post:
Bfenty (08-08-2017)
08-08-2017, 08:21 PM
#34
Pro
Hello Mako41,
One of the primary ingredients/agents of DEXCOOL is propylene glycol as shown below:
Primary agents
Methanol.
Ethylene glycol.
Propylene glycol.
Glycerol.
Maintenance
Traditional inhibitors.
Organic acid technology.
Hybrid organic acid technology.
Antifreeze - Wikipedia
https://en.wikipedia.org/wiki/Antifreeze
Lets agree on this ONE point. I would not use DEXCOOL in my lawnmower.
First, I am sorry if I was not clear, I said that "DEXCOOL was made using Propylene Glycol as one of the prime ingredients". Judging from the above chart I would assume that Propylene Glycol is in fact one of its prime ingredients, being #3 on the list.
Second, After my experience with the head gasket failure on my Buick I have been in touch with others dealing with this phenomenon. KNOWING that Propylene Glycol turns acid and can destroy metals like copper when it has seen overheating or overuse. Here below is a site that offers way more than I said to come to a similar point in the end.
This web site offers visual proof of what DEXCOOL can do to gaskets inside your engine.
http://www.zillamotorsports.com/DEX/
When DEXCOOL came out they advertised it as being a "Safe, non-toxic" anti-freeze. The initial anti freeze that came in my 2005 Buick was red, not orange or green.
Dexcool is listed as being good for FIVE years or up to 100,000 miles. Mine was nine years old but was treated by the Buick mechanics with some conditioners or additives.
"So it’s true that DexCool caused gasket leaks, but the real problem was incompatibility between the plastic and the coolant. Everyone assumes the problem was Dex-Cool, when in fact, the problem was the type of gasket material combined with the use of Dex-Cool. GM has redesigned the gaskets that the problem has now been fixed."
" Shops reported other problems with DexCool engines besides the 3.1 and 3.4-liter engine. Specifically, shops reported sludge buildup, especially in cast iron engines. But after a thorough investigation, it turns out that the only time sludge builds up is if the engine is low on coolant. When engines run low on coolant, the organic acid technologies oxidize and cause iron oxide deposits. The “rusting” usually NOT affect newer aluminum engines. But, running ANY engine when it’s low on organic acid type coolant cause form sludge."
Sludge can form in the presence of Dex-Cool coolant exposed to the atmosphere or in air pockets in the cooling system, (C4's are notorious for this) some C4 open to the atmosphere coolant recovery tanks also allow Dex-Cool to form sludge
Both of the preceding quotes are from this website:
http://ricksfreeautorepairadvice.com/is-dexcool-bad/
MAKO41 it seems that we are close in our thoughts regarding the use of DEXCOOL. With my personal experience with one of the main ingredients, I KNOW for a fact that propylene glycol does not belong in automobile engines.
I have been attacked personally for making statements against DEXCOOL on this site before. There is plenty of evidence that it works on some vehicles if it is replaced or replenished as necessary.
The more I read and learn about this red anti-freeze the less likely I would ever want to use it. They claim that GM has finally solved all the gasket issues and that all is well in the GM world.
Regarding the use of plain old propylene glycol for an anti-freeze in cars or even my C4. That would never happen as it is not designed for that kind of use.
I would use plain distilled water in my radiator (with a 16 lb cap on the radiator) before I will ever use DEXCOOL again.
I apologize if I have offended you by my choice of words. I was simply trying to show the OP that this might be a cause of what he was seeing in his engine IF he was using or had used DEXCOOL in his Corvette.Yes that's what I was trying to say as well!
My goal here was to try to help other Corvette owners understand the pitfalls of using this anti-freeze. I am simply trying to help others!
Have a great day and may you remember to change the Ethylene Glycol based (GREEN) anti-freeze every two years as directed by the manufacturers.
One of the primary ingredients/agents of DEXCOOL is propylene glycol as shown below:
Primary agents
Methanol.
Ethylene glycol.
Propylene glycol.
Glycerol.
Maintenance
Traditional inhibitors.
Organic acid technology.
Hybrid organic acid technology.
Antifreeze - Wikipedia
https://en.wikipedia.org/wiki/Antifreeze
Lets agree on this ONE point. I would not use DEXCOOL in my lawnmower.
First, I am sorry if I was not clear, I said that "DEXCOOL was made using Propylene Glycol as one of the prime ingredients". Judging from the above chart I would assume that Propylene Glycol is in fact one of its prime ingredients, being #3 on the list.
Second, After my experience with the head gasket failure on my Buick I have been in touch with others dealing with this phenomenon. KNOWING that Propylene Glycol turns acid and can destroy metals like copper when it has seen overheating or overuse. Here below is a site that offers way more than I said to come to a similar point in the end.
This web site offers visual proof of what DEXCOOL can do to gaskets inside your engine.
http://www.zillamotorsports.com/DEX/
When DEXCOOL came out they advertised it as being a "Safe, non-toxic" anti-freeze. The initial anti freeze that came in my 2005 Buick was red, not orange or green.
Dexcool is listed as being good for FIVE years or up to 100,000 miles. Mine was nine years old but was treated by the Buick mechanics with some conditioners or additives.
"So it’s true that DexCool caused gasket leaks, but the real problem was incompatibility between the plastic and the coolant. Everyone assumes the problem was Dex-Cool, when in fact, the problem was the type of gasket material combined with the use of Dex-Cool. GM has redesigned the gaskets that the problem has now been fixed."
" Shops reported other problems with DexCool engines besides the 3.1 and 3.4-liter engine. Specifically, shops reported sludge buildup, especially in cast iron engines. But after a thorough investigation, it turns out that the only time sludge builds up is if the engine is low on coolant. When engines run low on coolant, the organic acid technologies oxidize and cause iron oxide deposits. The “rusting” usually NOT affect newer aluminum engines. But, running ANY engine when it’s low on organic acid type coolant cause form sludge."
Sludge can form in the presence of Dex-Cool coolant exposed to the atmosphere or in air pockets in the cooling system, (C4's are notorious for this) some C4 open to the atmosphere coolant recovery tanks also allow Dex-Cool to form sludge
Both of the preceding quotes are from this website:
http://ricksfreeautorepairadvice.com/is-dexcool-bad/
MAKO41 it seems that we are close in our thoughts regarding the use of DEXCOOL. With my personal experience with one of the main ingredients, I KNOW for a fact that propylene glycol does not belong in automobile engines.
I have been attacked personally for making statements against DEXCOOL on this site before. There is plenty of evidence that it works on some vehicles if it is replaced or replenished as necessary.
The more I read and learn about this red anti-freeze the less likely I would ever want to use it. They claim that GM has finally solved all the gasket issues and that all is well in the GM world.
Regarding the use of plain old propylene glycol for an anti-freeze in cars or even my C4. That would never happen as it is not designed for that kind of use.
I would use plain distilled water in my radiator (with a 16 lb cap on the radiator) before I will ever use DEXCOOL again.
I apologize if I have offended you by my choice of words. I was simply trying to show the OP that this might be a cause of what he was seeing in his engine IF he was using or had used DEXCOOL in his Corvette.Yes that's what I was trying to say as well!
My goal here was to try to help other Corvette owners understand the pitfalls of using this anti-freeze. I am simply trying to help others!
Have a great day and may you remember to change the Ethylene Glycol based (GREEN) anti-freeze every two years as directed by the manufacturers.
Coolant color is just a dye.... Keep in mind virtually all coolants are Ethylene Glycol based the differences between them lye in the different chemical corrosion inhibitor packages they contain, be it IAT, OAT, HOAT, NOAT ect, and the color each manufacturer chooses to dye them.
No offense taken as I am trying to help out others on this forum from the been there done that point of view.... as you appear to be as well!
We can both agree that GM OAT type Dex-Cool and its clones, (that would include all coolants currently offered by Prestone BTW) can be a bad coolant choice for our C4's and should probably be avoided at all costs. There are many better alternatives to OAT type Dex-Cool from old fashioned IAT coolant, that should be changed annually to long life HOAT type coolant, to be change every 5 years or 100Kmiles, ect.
A Propylene Glycol coolant should never be used in a C4 as the entire cooling system was never designed to use it. Bad things will probably occur to seals, gaskets and other cooling system components using an environment friendly Propylene Glycol coolant!
Not sure why you seem to think Dex-Cool is a Propylene Glycol coolant though?? It is not.... It is an Ethylene Glycol Based Coolant with an OAT or Organic Acid Technology chemical corrosion inhibitor package added. It may contain some small amounts of other ingredients but let me be clear it is not a Propylene Glycol based coolant. If you believe that you have been misinformed.
Last edited by mako41; 08-08-2017 at 08:46 PM.
