Originally Posted By: Moab
Originally Posted By: SteveSRT8
All baloney in my experience.
I own and maintain a fleet of GM vehicles including 3500 Savanas and Silverados. After having breakfast with the actual development engineer on the "G" team at GM in charge of vans I have stopped maintaining any factory Dex equipped vehicle until something breaks in the cooling system.
This is almost always in excess of 200k miles, and sometimes even more.
We have open recovery tanks on some and sealed recovery tanks on others. No difference, our factory Dex fill is clear and clean with NO SLUDGE of any kind.
The Dex thing is long over with, and is kept alive by misinformed folks on the Internet. Even Ford is using Dex now. Think about it.
Note that the OVERWHELMING majority of GM owners have had no issues since the bad gasket issue was resolved years ago.
My dad owns a 2001 Chevy Impala. This car only has 55,000 miles on it today. The check engine light came on for low coolant level even though the car was completely full of Dex Cool coolant, so they had the local Chevy dealer check the car out and the dealer could find nothing wrong with the car.
My dad had a local independent mechanic he trusts check the Impala out. This mechanic said he knew exactly what the problem was. He said the sensor in the radiator is being gummed up by the Dex Cool. This mechanic recommended flushing the Dex Cool out and refilling it with a different kind of coolant other than Dex Cool. My dad did have him flush out the cooling system, had him refill it with a non Dex Cool coolant the mechanic recommended and the check engine light for low coolant level has stayed off!
I do not know this mechanic and have never talked to him, but many professional mechanics do not like Dex Cool. My dad told me this story last week about his car.
As I've said before, poor maintenance and poor design, not poor coolant.
On the surface, this seems a cut and dried case against Dex, but it's not.
Lets start with poor design. These cars have a stupid angle on the filler neck making them hard to fill and keep full. Now to move on to poor maintenance... Dex is a 5 year coolant. Has it ever been replaced? If not, the current fill would have been 11 years old. Has the radiator cap ever been replaced? Is there air in the system? If no, no and yes, then there's no wonder the level sensor was gunked up.
On the topic of the coolant light staying off, the mechanic could have simply replaced the malfunctioning sensor and the light still would have gone off...
