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GM Lawsuits: Dex-Cool to blame??


Well-known member
Aug 11, 2004
Shelbyville, IN
1993 Black & Silver LT1 A4 Coupe
I just heard about this, Googled it and found that it appears to be true. I don't know how to comment on it and have my opinion but thought you all would like to know as well.

Dex-Cool is being blamed for corroding cooling systems and causing costly repairs to GM vehicles. Early failures on many engine parts; water pumps, radiators, intakes, heater cores, etc.

Actually, I know someone with a 2006 Monte Carlo that has already been in the shop to replace the water pump.

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Aug 25, 2003
Clayton, NC
'63 Coupe, '72 Convert, '02 Z06
My problem with Dex Cool is that it is more maintenance intensive and less forgiving than the old green Ethylene Glycol. Yes, it may have some advantages over the green glycol (Dex Cool is still ethylene glycol), but unless properly and constantly maintained, it WILL create problems. Some of the problems were with GM design, i.e, the weighted radiator cap used in some of the S-10 vehicles. This allowed air into the system and air seems to cause Dex Cool to degrade.

I understand what GM was attempting to do when they converted to Dex Cool but will NEVER understand why they went to a system that requires more maintainance than what was used previously. Most people do not maintain their cars (Corvette owners excluded). And it also seems that even if the routine maintenance requirements were met, problems with Dex Cool could still occur. My daughter has a 2000 Jimmy which as been maintained by the book, but has a plugged heater core due to Dex Cool. You have to remove the entire dashboard to access the heater core; a job I do NOT look forward to.

Consequently, I dumped the Dex Cool from my '02 Vette ASAP after purchase and installed HOAT anti freeze (Dex Cool is OAT). HOAT type (yellow) seems to have all of the advantages as Dex Cool without the disadvantages. Maybe that is why all of the car manufactures other than GM install it at the factory.

Be aware that any GM vehicle built 1996 to today, expecially the S-10 variants, the mini-vans and some of the trucks are all subject to expensive Dex Cool problems. Caveat Emptor!



I currently have my LT4 down for radiator cleaning, new filters, hoses, etc., basically a winter project to clean up and detail the motor. So, now I'm having second thoughts about refilling with Dex-Cool. Only 23,500 on the clock and the coolant that came out looked really clean. Also, I read the link on the post by C4Tom and at the end of the article, it says that mechanics are recommending to NOT change to a different coolant if Dex-Cool was the factory spec.

Like to hear some other thoughts.

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