Hi All,
I was just told that the 5yr (orange DEX antifreeze) gunked up the radiator and is the cause for engine overheating. This was passed on but originated by a GM Goodrench mechanic. He said get rid of it ASAP. Anyone heard of anything similar?
Thanks

 

More likely that someone mixed an incompatable fluid with the DEX (like Prestone) or bad tap water. I changed out my DEX after 70K and 8 years and it was like new

 

Please do a thread search here (General) and in Tech and you will find a whole lot of information.

 

Here we go again. The DEXCOOL controversy that just won't die.

DEXCOOL antifreeze was an issue in some late '80s and '90s GM vehicles that had the 2800cc V6 motor with poorly engineered water pump gaskets and/or the owners failed to maintain their cooling systems properly.

Adding to the problem, GM at that time added supplemental tablets to the cooling system. When air was allowed to enter the cooling system through poor maintenance practices, the mixture sometimes turned the DEXCOOL to a murky thickening liquid. That did cause cooling issues and damaged the gaskets.

It did not happen to every GM vehicle. I had a 5.7L '96 Impala SS and a 4.3L '98 S10 truck, neither of which were effected by DEXCOOL/tablets.

Since then GM has improved the gasket technology and no longer uses the tablets. It's not an issue now.

Go to the C5 Tech forum. Click on search or search this forum (in the red banner).

Use "dexcool" as the keywords and do your own research so you know the facts.

If that doesn't convince you, change your coolant to some other manufacturer. Know that you must remove all traces of the DEXCOOL from the system if you intend to use "green" coolant to avoid contamination and resulting issues. And also know that if you chose to use "green" coolant, it is not necessarily safe for aluminum components as is the orange extended life products, and will more than likely have to be replaced on a more frequent basis than orange extended life antifreeze.

 

2 gallons of distilled water and water wetter for the summer problem solved.

 

Sorry for my ignorance but what is a water wetter? Is it compatable with DEXCOOL? I just changed my radiator, flushed and replentished 50/50 distilled water and the DEX.

 

http://www.redlineoil.com/product.aspx?pid=74&pcid=10

I did a complete flush got all my coolant out of the system, added the distilled water and 2 bottles of the water wetter. runs nice and cool. we have 100*+ days here and the asphalt can get upwards of 200 degrees radiating into the engine bay. the hottest i run is between 195-207*w/ ac on.

 

After I changed my rad I got rid of DEX cool and went with a regular 50/50 mix.

 

That's crazy when people make statements like that, now it will be difficult to have much confidence in them in the future.

Water wetter as mentioned is a replacement for antifreeze. You must flush your system first very well, then add distilled water with the proper amount of water wetter. And that's all if you go that route.

Referring to your Owner's Manual, Scheduled Maintenance, at 150,000 miles, drain, flush and refill the cooling system (or every 60 months since last service which ever occurs first).

Some service procedures require draining the coolant system (removing throttle body for example) so that's the reason for the "since last service" is there.

So basically service the coolant (DexCool) every 5 years or 150,000 miles whichever occurs first. In most of our cases the 5 years occurs first.

 

I'd be a little weary for those who choose to run water with water wetter all year round regardless of what climate you live in. Water wetter is solely an additive and is not a coolant. Most racers use it (I use it in my race bike) but I also change my fluid every summer. Water wetter does work best when mixed solely with water, hence forth why it is used mostly in race applications. Long term use can cause corrosion as it does not have anti corrosive properties and is not a coolant.

A small tid bit of info...

Water Wetter - It is an additive product. Water Wetter is what is called a “surfactant.” What this means is that it reduces the surface tension of the water or in other words, it allows the water/fluid to “rub” closer to the metal allowing it to better draw off heat. Water Wetter works and it is good stuff. However, if you add it to an EG antifreeze product your results are minimal. It will reduce temperatures, but by only a small amount. Added to water, you will see a significant difference in temperature reduction. But it will not raise the boil point of the water nor does it offer any antifreeze protection. So your engine may run a bit cooler, but when it gets hot it will “spit out” the coolant before other products do. That is not good, because now you’ll have less coolant in the engine. Using more than the recommended amount (4 capfuls to a quart) is a waste and it will not make any difference, only use their recommended amount.

 

While I can't speak for every car out there, I've had three C5s and all have had DexCool in them - never had one problem with them. Have changed the coolant in two of them (normal maintenance) and the old coolant still looked great.

 

There is NOTHING wrong with the Chemical construction of DexCool. If you flush your system and change the DexCool once every five years you will never have a problem with DexCool. If using DexCool is a problem for you, Contact the EPA. They mandated that all cars made after a certain, (I can't remember right now) date must use a coolant that is safe for the environment. But the chemical compound is a very effective and adequate Coolant. I don't a thing about "waterWetter" Makes water weter? Sound kinda like snake oil to me, but what do I know. Just flush your system every five year with DexCool and your engine will be fine, But make sure it's not leaking, cause that is going to cause a problem !

 

I haven't seen the old "green" coolant for years all of it is compatible these days with Dexcool

"Autozone full strength extended life antifreeze and coolant is recommended compatible and formulated for use with any antifreeze/coolant in any make or model of car or light duty truck with aluminum and other engine metals."

Organic acid technologyCertain cars are built with organic acid technology (OAT) antifreeze (e.g., DEX-COOL[13]), or with a hybrid organic acid technology (HOAT) formulation (e.g., Zerex G-05[14]), both of which are claimed to have an extended service life of five years or 240,000 km (150,000 miles).

DEX-COOL specifically has caused controversy. Litigation has linked it with intake manifold gasket failures in General Motors' (GM's) 3.1L and 3.4L engines, and with other failures in 3.8L and 4.3L engines. Class action lawsuits were registered in several states, and in Canada, to address some of these claims. The first of these to reach a decision was in Missouri where a settlement was announced early in December 2007.[15] Late in March 2008, GM agreed to compensate complainants in the remaining 49 states.[16] GM (Motors Liquidation Company) filed for bankruptcy in 2009, which tied up the outstanding claims until a court determines who gets paid.[17]

According to the DEX-COOL manufacturer, "mixing a 'green' [non-OAT] coolant with DEX-COOL reduces the batch's change interval to 2 years or 30,000 miles, but will otherwise cause no damage to the engine."[18]

According to internal GM documents,[citation needed] the ultimate culprit appears to be operating vehicles for long periods of time with low coolant levels. The low coolant is caused by pressure caps that fail in the open position. (The new caps and recovery bottles were introduced at the same time as DEX-COOL). This exposes hot engine components to air and vapors, causing corrosion and contamination of the coolant with iron oxide particles, which in turn can aggravate the pressure cap problem as contamination holds the caps open permanently.[19]

Typically OAT antifreeze contains an orange dye to differentiate it from the conventional glycol-based coolants (green or yellow). Some of the newer OAT coolants claim to be compatible with all types of OAT and glycol-based coolants; these are typically green or yellow in color (for a table of colors, see [12])

 

I have had no such issues at all!

Thanks,Matt

 

Nothing is compatible with DEXCOOL, not even DEXCOOL is good enough to be mixed with DEXCOOL. DEXCOOL is a magic liquid that, once removed, no other liquid can take it's place, not even DEXCOOL itself!

 

 

If I recall the water wetter is a long chain surfactant which will break down after time in the cooling system. I know this is over kill but I change out my Dex-Cool every two yrs. I still have the orginal water pump on my '99 FRC.