DEX-COOL problems?
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Melting Slicks
Joined: Aug 1999
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From: Whidbey Island Washington
DEX-COOL problems?
How many of you had proplems with DEX-COOL in your Vettes or other GM motors? I understand Girard Gibbs & DeBartolomeo law firm is investigating claims in connection with a proposed class action against GM & Cheveron/Texaco concerning DEX-COOL. I've not had problems with any of my Vettes (YET) but have serious problems with our '98 Cadillac after ONLY 64K miles because DEX-COOL FORMED A SLUDGE-LIKE SUBSTANCE THAT CLOGED THE COOLING SYSTEM CAUSING IT TO OVERHEAT. I also understand the class action findings include DEX-COOL corroding all parts of the engine it comes in contact with including heater core, water pump, hoses, cap, upper and lower intake mainfold, theremostat and engine block. How would I flush DEX-COOL from my '96 CE? A local Chev dealer charges $700 for a cooling system flush with special flushing equipment and then ONLY reinstalls DEX-COOL!
Team Owner
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I haven't had any Dex Cool problems with any of my GM cars, but $700.00 for a radiator flush! They do it much cheaper at the 10 minute oil change a mile from my house! 
Team Owner
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From: At the beach in little Rhody
No problems here, and I have switched all my green coolant cars to Dexcool. Problems usually occur when the system gets low or the improper mixture is used. I went into my motor block and the radiator with a boroscope and both were absolutely clean as a whistle.
Le Mans Master
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Bill
No problems with my 96 GMC Yukon with 125K on it (first year that they started using DEX (to my knowledge).
The only serious problem that I know of is this. If someone accidently puts the green in the vehicle, internal corosion will occur because the green has some sort of silica compound in it that DEX cooled engines metalurgy cannot cope with.
Mark
No problems with my 96 GMC Yukon with 125K on it (first year that they started using DEX (to my knowledge).
The only serious problem that I know of is this. If someone accidently puts the green in the vehicle, internal corosion will occur because the green has some sort of silica compound in it that DEX cooled engines metalurgy cannot cope with.
Mark
Last edited by Mr. Peabody; Oct 20, 2004 at 12:17 PM.
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I haven't PERSONALLY had any issues with Dex-cool, but my mother's 1998 Blazer had exactly the same issue. The owner's manual clearly states that the coolant should be changed after 5 years in service. The service writer at the dealership told me that air had probably gotten into the cooling system causing it to sludge up.
Once I heard her nightmare, I took my 1998 Blazer in with about 54K and had it drained and flushed. I've got Dex-cool in my 1998 Vette and have no issues. Since I bought the car a year ago, I can't vouch for the originality of the coolant - it may have been flushed and refilled by the previous owner.
Check your owner's manual regarding the service intervals.......
Once I heard her nightmare, I took my 1998 Blazer in with about 54K and had it drained and flushed. I've got Dex-cool in my 1998 Vette and have no issues. Since I bought the car a year ago, I can't vouch for the originality of the coolant - it may have been flushed and refilled by the previous owner.
Check your owner's manual regarding the service intervals.......
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Originally Posted by ZRWON
How many of you had proplems with DEX-COOL in your Vettes or other GM motors? I understand Girard Gibbs & DeBartolomeo law firm is investigating claims in connection with a proposed class action against GM & Cheveron/Texaco concerning DEX-COOL. I've not had problems with any of my Vettes (YET) but have serious problems with our '98 Cadillac after ONLY 64K miles because DEX-COOL FORMED A SLUDGE-LIKE SUBSTANCE THAT CLOGED THE COOLING SYSTEM CAUSING IT TO OVERHEAT. I also understand the class action findings include DEX-COOL corroding all parts of the engine it comes in contact with including heater core, water pump, hoses, cap, upper and lower intake mainfold, theremostat and engine block. How would I flush DEX-COOL from my '96 CE? A local Chev dealer charges $700 for a cooling system flush with special flushing equipment and then ONLY reinstalls DEX-COOL!
I've done one flush since buying mine in '99 and the coolant looked just fine. I flushed and changed it anyway (using distilled water). It still looks fine with 97K miles.
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Just opened the radiator cap on my 2002 Monte Carlo 2 weeks ago and at the top of the neck was the Sludge you are probably talking about. It was like F*&%ng mud. Flushed the system 2 times to get it somewhat clean.
Car has 31k on it and I was shocked to see this 'mud' that rose to the top.
I'll have to investigate this story you mention above.
Car has 31k on it and I was shocked to see this 'mud' that rose to the top.
I'll have to investigate this story you mention above.
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No problems with my engine using Dex-Cool. Just had it flushed and refilled this spring since it has four years on the stuff. Dealer charged me less than $50 for the flush and fill.
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The common issue seems to be the vehicles with cast iron blocks - the Cadillac, Glenn's Monte Carlo, my mother's Blazer, seem more prone than those with aluminum blocks (like the LS1) - curious, huh? 
Also - I wonder if the $700 the dealer was going to charge for the flush has anything to do with getting all that mess out of the engine, radiator, heater core, etc. I think my mom's repair bill was in the $1800 range - and that was having the radiator dipped in acid or something to get out that S**T out of there!
Also - I wonder if the $700 the dealer was going to charge for the flush has anything to do with getting all that mess out of the engine, radiator, heater core, etc. I think my mom's repair bill was in the $1800 range - and that was having the radiator dipped in acid or something to get out that S**T out of there!
Last edited by blacksedan87; Oct 20, 2004 at 12:49 PM.
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One of our mechanics at our shop (we run a tucking business) said that the iron block w/ aluminum heads in my Monte Carlo could very well be the contributing factor.
Melting Slicks
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From: Northville Michigan
Bill,
Generally, individuals neglect to change the DEXCOOL every two years as it recommends. Then you can get into some of the problems you have read about.
Because I plan on keeping my Z06 for a number of years, last April I drained the DEXCOOL out of my cooling system, including the engine block (removed the block's drain plugs), flushed the system with Prestone Super Flush, and installed Evans NPG+ waterless, lifetime coolant - www.evanscooling.com. The hardest part was getting at the block drain plugs.
Also, the NPG+ does a better job of elimating the hot spots in the cylinder heads and on the upper cylinder walls that lead to detonation. I will never have to replace my coolant again. Good luck with your decision.
Generally, individuals neglect to change the DEXCOOL every two years as it recommends. Then you can get into some of the problems you have read about.
Because I plan on keeping my Z06 for a number of years, last April I drained the DEXCOOL out of my cooling system, including the engine block (removed the block's drain plugs), flushed the system with Prestone Super Flush, and installed Evans NPG+ waterless, lifetime coolant - www.evanscooling.com. The hardest part was getting at the block drain plugs.
Also, the NPG+ does a better job of elimating the hot spots in the cylinder heads and on the upper cylinder walls that lead to detonation. I will never have to replace my coolant again. Good luck with your decision.
Burning Brakes
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From: Dardenne Prairie Missouri
I've not had any problems with any of my GM cars with Dex-cool. I've got a '96 Cavalier which was flushed 2 years ago for about $70 bucks at the dealer and I had a '97 Cavalier Z24 which my brother now owns and of course the '03 Vette and the '04 Vue. None have experienced any problems, just do what GM says in the manual and you should be fine. Just my .02.
Burning Brakes
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Problems with DexCool occur when people don't maintain the cooling system. The attorneys are working on the premise that you don't have to even look at the cooling system for 6 years or 100,000 miles.
Basically Dexcool creates a thin layer of corrosion within the cooling system, to prevent further corrosion. (Same theory on steel bridges to prevent them from rusting through!) That's why you don't want to mix Antifreeze and Dex. Dexcool problems occur as stated above, when the cooling system is low, and/or has air in the system.
As with many things, the problems occur through neglect and lack of maintenance. Those of us who crack the hood and open caps and tops probably will realize there's a problem before it's catastrophic.
Unfortunately for GM, they implied that DexCool made your system maintenance free, and probably will have to pay the Trial Lawyers for that marketing blunder.
Basically Dexcool creates a thin layer of corrosion within the cooling system, to prevent further corrosion. (Same theory on steel bridges to prevent them from rusting through!) That's why you don't want to mix Antifreeze and Dex. Dexcool problems occur as stated above, when the cooling system is low, and/or has air in the system.
As with many things, the problems occur through neglect and lack of maintenance. Those of us who crack the hood and open caps and tops probably will realize there's a problem before it's catastrophic.
Unfortunately for GM, they implied that DexCool made your system maintenance free, and probably will have to pay the Trial Lawyers for that marketing blunder.
Team Owner
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From: At the beach in little Rhody
Check this article. GM and Texaco have done studies and there is a common theme. Like I stated above, I have it in all my cars with absolutely no problems and the blocks and radiators are super clean.
DEXCOOL Symposium Paper
One more article
DEXCOOL Symposium Paper
One more article
Cherish your Hopes...
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From: West Palm Beach FL
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Originally Posted by Glennm27
Just opened the radiator cap on my 2002 Monte Carlo 2 weeks ago and at the top of the neck was the Sludge you are probably talking about. It was like F*&%ng mud. Flushed the system 2 times to get it somewhat clean.
Car has 31k on it and I was shocked to see this 'mud' that rose to the top.
I'll have to investigate this story you mention above.
Car has 31k on it and I was shocked to see this 'mud' that rose to the top.
I'll have to investigate this story you mention above.
...Im getting mine flushed tomorrow...I'll let you know how bad then...
