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I was reading (on the internet) all the problems people were having with Dex-cool and I didnt know if GM was still using it. I read that Gm is going to/has settled a class action because of dex-cool.


Anyone hear anything?

Thanks
 

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The problem with Dex-Cool (and any anti-freeze) is that there is no such thing as "permanent" anti-freeze. GM made a huge mistake in claiming 5 years or 100,000 miles (or whatever it was) for Dex-Cool. People who tried to go that long without changing a/f got head gasket leaks.

The problem is that a/f has additives that retard the galvanic reaction between dis-similar metals. Depending on what the head gaskets are made of, the cooling system contains different metals at various places such as copper, aluminum, iron/steel, etc. Additives are included to retard (not prevent) erosion. The additives wear out and you lose (usually) a head gasket because that's the thinnest place for a leak.

Forget the manual and change a/f every year or two. Dex-Cool is good stuff, just don't treat it as superior to ordinary a/f and you'll be OK. The reason GM blew it (IMHO) is that in their testing, they put a lot of testing miles on the cars in short periods of time. The general public stretches mileage out over years, not months, and the time caught up with them after Dex-Cool had been on the street for a few years.
 

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I am the original owner of a '96 Impala SS which had Dex-Cool as the coolant from GM. I have changed the coolant every 5 years including taking the knock sensors out to drain the block and I have not had any problems. I have changed the Dex-Cool twice in the last 12 years.
Some in the Impala community have had problems mainly with plugged heater cores with Dex-Cool and the belief among many is that it is not the Dex-Cool but the clay tablets that were added to the Dex-Cool at delivery. I think GM quit adding the tablets a number of years ago. The tablets also changed the color of the Dex-Cool from a bright orange to a dirty rust color. You could actually see particles of the clay tablets floating in the coolant. It didn't concern me enough to change to ethylene glycol since my Dex-Cool never got rusty and remained clear. If it is a concern, you could change to ethylene glycol and it wouldn't hurt a thing except decrease your maintenance time interval schedule for coolant flushes/ replacement. Instead of coolant replacement every five years with Dex-Cool, with ethylene glycol it would be around every two years.
 

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No problems with Dex-Cool in my '96 Firebird Firehawk. However, I can not say the same thing about my '06 Grand Prix GXP. I've had sludge issues and missing coolant. The Service Rep.'s response to this was: "it's probably just some sand that worked its way out from the various castings". Yep, this is the service department I work with. There are other less convienant ones around, but I keep going back for my punishment.
 

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No problems with Dex-Cool in my '96 Firebird Firehawk. However, I can not say the same thing about my '06 Grand Prix GXP. I've had sludge issues and missing coolant. The Service Rep.'s response to this was: "it's probably just some sand that worked its way out from the various castings". Yep, this is the service department I work with. There are other less convienant ones around, but I keep going back for my punishment.
A lot of people erroneously think that Dexcool has caused sludge. It's usually the cooling sealant tabs that GM puts into the cooling system. It resembles a brown sludge and tends to collect in the overflow bottle and right around the radiator cap. This residue is harmless.
 

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If I was to bring my car in for a coolant flush to a service dept, do they flush it tap water or distilled water?
Tap water. If you want it done with distilled water you are probably going to have to do it yourself. I'm sure they'll be glad to tell ya they used distilled water though.
 
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