GM Owners Still Steaming Over Dex-Cool

Dex-cool Contamination

 

Thats a good way to get repair work I guess. Sounds like GM will lose quite a few customers over that. I've always been a plain old Prestone green stuff guy myself. Prestone always seems to do well for me and my 74' has the original radiator in it and its clean yet.

Pics here http://www.sancarlosradiator.com/dex-cool_pics.htm

 

Im y experience the GM dex cool as been trash. I have countless customers who have bad intake gaskets, stuffed heater cores in GM vehicles that have that crap in them. In out shop, we like to use coolant similar to the ford gold, it rated for use in all vehicles.

 

I have a '98 K 1500 with 124,000 mi. on it and I haven't had any problems yet (hope I don't curse myself by saying that). I've heard you can switch to the green stuff but you have to do a thorough flush and change hoses or something like that. Since I've not had any problems I'm not gonna change. I have been changing my fluid at least every three years and every two as a rule. I've never noticed any goo, gel or anything like that. But I've made sure to not allow any air pocket in the radiator either. I've heard that if you allow an air pocket in the radiator it promotes the growth of the dreaded gel and what not. Maybe I got lucky!

 

Why does GM specify Dex-Cool instead of traditional etheylene glycol coolant anyway? What is different about their engines? Nothing that I can tell. Cast iron and aluminum, same as the rest

 

Have no idea. Do they have the patent on it or get a kick back who knows.

 

You changing your fluid is what has helped you out. When people dont, or do like GM says, the stuff usually cakes up inside the engines. Chage it regularly, and your fine.

 

Exactly, hes changing the coolant long before the GM recommended interval.

 

A lot of the problems people have with Dex-cool comes from them mixing the green coolant with it. It just shouldn't be done. Fordgery isn't having any problems because he hasn't mixed it with anything else and he is changing it regularly. Thats another key with Dex, change it on or before the recommended intervals. I use the reguular old green ethylene glycol in everything I own, Ford and Dodge. I won't buy a used GM that may have been spec'ed for Dex simply because I don't konw what previous owners have done with the coolant before. I would buy a brand new vehicle with it and not worry about it at all.

Chris

 

When I worked at a bus company we used the gm dex-cool. we would end up having to replace water pumps, radiators. heater cores, etc. We would get to the point where we installed shut off valves in the heater hoses so we could make them last longer.

 

Replacing the Dexcool with regular anti freeze doesn't seem to cause problems. A friend of mine had a lumina which shat the intake gaskets, so when he bought his monte carlo, drained the dexcoool, installed green. All was good.

 

I remember when I was in trade school in the mid 90s, this stuff was introduced. Even back then it seemed to have the tendency to produce the brown gunk, corrode things, and stop up radiators and other small orifices. All of this is just validation of things I had long suspected.

I have a few gallons of the stuff sitting around. I guess it should go straight to the recycling bin at the local parts house.

 

DEXcool came into existence in the early 90's, the older green coolant was corrosive to aluminum and since GM was using extensive amounts of aluminum in their engines they came up with DEXcool. You can switch to plain ol green coolant, as its no longer corrosive to aluminum, but you cannot mix the two at all. GM's service interval is the problem as long as you flush and change you coolant like you normally would you'll be fine.

 

A mechanic told me the older green stuff caused problem in aluminum blocks because of phosphates in the coolant. But there are no phosphates in the new Prestone 50/50 green coolant ($8 a gallon at Walmart). They claim it can be mixed with any coolant, including Dex-Cool?



"Q. Does Prestone® Antifreeze/Coolant contain phosphates?

A. Some European automobile manufacturers request that a phosphate-free antifreeze be used in their vehicles. This issue is related to the extremely high mineral content of the water in Europe. If you were to mix an antifreeze that contained phosphates with the type of water they have in Europe, it may produce deposits that can settle in the cooling system and promote corrosion. However, in North America we do not have this type of water problem. Typical North American coolants have contained phosphates (which is part of the corrosion inhibitor package) for many years. Therefore, the question of phosphates is a non-issue here in North America. Prestone® Antifreeze/Coolant is completely safe for use in both foreign and domestic vehicles. For those consumers who would feel more comfortable using a phosphate-free antifreeze, our Prestone® Extended Life 5/150 Antifreeze/Coolant is phosphate, silicate, and borate free. This coolant uses a special chemistry and technology that extends the life of the corrosion inhibitor package so that it lasts for five years or 150,000 miles (whichever comes first), and is safe for all cars and light trucks (old or new). Prestone® Extended Life 5/150 Antifreeze/Coolant has been approved by General Motors under their DEX-COOL® specifications and is compatible with other DEX-COOL® approved coolants."

Prestone :: Car Care : FAQ