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GM's New DEXCOOL Systems

4K views 18 replies 16 participants last post by  syclone 
#1 ·
OK guys I'm very new to this group so forgive my if I don't know any names. :rolleyes: Anyhow my question is how safe is the new Dex-cool system? anyone ever tried it yet? I have heard if you run it low that it will start to eat at the block from the inside out taking the freeze plugs first. GM has concocted this stuff to be a low maintenance coolant but if it damages the motor I would rather replace the old green antifreeze every fall. Please give me your opinion.

Thanks.
Holder350...
 
#2 ·
garbage

GMs dexcool systems are crap. you'd be farther ahead to flush the red stuff out and replace it with green. the red has a tendancy to gell up and clog your heater core leaving you to replace it. but if you replace the coolant. make sure you get all the red stuff out before you fill it with green or you'll have problems....
 
#6 ·
I have a fleet of chevrolets(7 chevrolets, 3 fords). I have not had good luck with the stuff. I can't for sure say that it was because of the coolant, but I have my suspicions. I do know that since I have switched to green I have not had the problems I had before. My trucks run 10 hours a day 5 days a week so things pop up a little faster than they would on a daily driver.

On another note not all my trucks have had problems(4 out of 7), but after a $1200.00 heater core replacement ( I didn't have time or gumption to do my self. They had to pull the whole dash out) I didn't want to take anymore chances.
 
#8 ·
I went through this not too long ago. Do a search on this site and on the internet. You will find plenty of reading and research. Most will be horror stories. Dexcool is a tricky coolant and can be TERRIBLE. After I researched for many many many hours, I flushed my system and went to the green stuff.

Dexcool is known to turn to brown goo. This can happen for several reasons (low coolant, leak in the cooling system (allowing air into it), not changing it soon enough. If it does turn to goo you heater core will be ruined, along with the other problems mentioned above.

I can tell you it VERY often doesn't make it to it's "scheduled maintenance".

As you can see some people have had no problems but, I can tell you a LOT of people have had "issues". There was/is even a lawsuit over this stuff.

Do your own research and make your own decision. What works for some doesn't work for others.

Royce
 
#9 ·
First the are compatable to the point that if you go from dexcool the standard you will see no issues because the system was not completely clean. If you go back to dexcool though it MUST be cleaned thoroughly. They are both ethlyne glycol based with dexcool having extra additives. Dexcool's biggest issue is air getting into the system as stated above it will gel and clog. It was intended for a better interval between maintenance times but IMO there is more upkeep than with standard because the drawback of running a little low or overheating can be more damaging with dexcool because of its temperment.
 
#12 ·
I have had considerable experience with Dex-Cool, extended life antifreeze.

As a shop owner, I have seen my share of GM's with the pink stuff in it. I have made 3 observations concerning the stuff. They are:

1. Vehicles that use Dex-Cool are consistently low on coolant levels when they come into my shop for routine service. I feel this is from small, multiple corrosive leaks that are caused throughout the engine and cooling system.

2. Dex-Cool seems to attack silicone type gaskets like the ones used on the Vortec V-8 (96-99), and the 3.1 and 3.4 V-6s used in Grand Ams, Buicks and GM vans, this causes internal and external coolant leaks. The gaskets themselves are of a poor design, and contribute to failures.

3. Dex-Cool has a propensity to get a pasty build up in it, particularly in areas around "o"-rings and gaskets, it also builds up in the coolant bottle.

I have been replacing the stuff whenever I can, because I feel that it's benefit is supposed to be long life, but with the leaks it creates, you wind up spending more adding coolant all of the time.

Good old green antifreeze is what I use to replace it, but only after thoroughly flushing the old out.
 
#13 ·
http://www.prestone.com/

"Because of advancements in vehicle technology, the antifreeze/coolant market has become nothing short of perplexing and burdensome," said Kelley O'Donnell, Product Manager for Prestone. "There are so many formulas on store shelves, some people have stopped changing or topping off their own antifreeze for fear they might add the wrong fluid. As a leader in antifreeze technology, we wanted to provide motorists with a formula that, when used as directed, could be used on any vehicle with no adverse effects."

The new Prestone All Makes All Models Extended Life Antifreeze/Coolant is unique in that it is compatible with any antifreeze/coolants on the market today. For example, if a vehicle has conventional coolant, which needs to be changed every two-three years or every 30,000 miles, adding the new Prestone All Makes All Models Extended Life Antifreeze/Coolant will maintain these properties. If a motorist adds it to a system that carries an extended life formula, which often times has a five-year or 150,000 mile change interval, it will provide these same characteristics.
 
#14 ·
camaroman7d said:
I went through this not too long ago. Do a search on this site and on the internet. You will find plenty of reading and research. Most will be horror stories. Dexcool is a tricky coolant and can be TERRIBLE. After I researched for many many many hours, I flushed my system and went to the green stuff.

Dexcool is known to turn to brown goo. This can happen for several reasons (low coolant, leak in the cooling system (allowing air into it), not changing it soon enough. If it does turn to goo you heater core will be ruined, along with the other problems mentioned above.

Royce
I own a 2000 Pontiac GrandAm, with the 204 cubic inch v6 in it (3.4L, metric people :rolleyes: ). I purchased it last June with about 116,800 miles on it and the coolant was brown; the cap came off in 2 pieces. I got a new OEM coolant cap and a bottle of GM radiator flush stuff. I forgot what they call it exactly, but I did that and refilled it with the pink stuff it came with. But, holy crap, it took forever to get clear water running in it there was so much crap built up in it. I peeked into the oil fill cap, and the inside of the heads/valvesprings appeared very clean, so it must've had it's oil changes on time. For horror stories and stuff on Dexcool, I go to www.gaownersclub.com. I'm ChevelleSSLS6, just slightly different than here. ;)
 
#16 ·
I'm running Dex in one of my cars and I haven't had any problems with it (knock on wood). One major thing to note is that if you plan on switching over to the green stuff, you MUST fully flush the system of all the Dex because the Dex and the green stuff have a violent reaction to one another. The only thing I've heard about problems switching over is that sometimes the coolant sensor needs to be replaced.
 
#17 ·
I made the switch in my 2000 GMC with no issues. I did flush the system EXTREMELY well first. I did not have to change any sensors.

I just looked under the hood of my company car 2004 Pontiac Grand Prix. I looked in the coolant recovery tank and guess what I saw, yep the brown goo is starting to form. This car only has 24K miles on it. Dexcool is supposed to be good for a 100K, right? NOT

I will be taking it to the dealer today to get the oil changed and have them take a look at the coolant (comapny car remember). I'll be sure to post back with the results.

If I owned it I would be flushing the system and making the change today.

Royce
 
#18 ·
NAIRB said:
2. Dex-Cool seems to attack silicone type gaskets like the ones used on the Vortec V-8 (96-99), and the 3.1 and 3.4 V-6s used in Grand Ams, Buicks and GM vans, this causes internal and external coolant leaks. The gaskets themselves are of a poor design, and contribute to failures.
Yup, that's how I got my '97 Vortec. It destroyed the intake gasket around the water port that feeds the thremostat housing. Lucky me! :D
 
#19 ·
One major thing to note is that if you plan on switching over to the green stuff, you MUST fully flush the system of all the Dex because the Dex and the green stuff have a violent reaction to one another. The only thing I've heard about problems switching over is that sometimes the coolant sensor needs to be replaced.


This is completely untrue. I have been told this also by other gm techs. The first thing I learned about the dexcool system in my training was it is ALSO ethlyne glycol based. If you are going from dexcool to standard you do not have to have a thorough flushing but going the other way you need to. I have been running my wife's 2000 Impala since new with dexcool and only adding standard when low. I have not had a single problem with the cooling system malfunctioning on this car.
 
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