Dex-Cool - keep it or swap it?

[LeakySeals]

I like to use factory fluids. But I don't use the factory maintenance intervals. Everything early and often. So I suppose 30k drain and fills of Dex-Cool may give me good results. Dex-Cool concentrate is at Walmart cheap $14.97. I use distilled as the mix?

 

[dave1251]

Yes that will be ideal.

 

[crazy8]

Originally Posted By: LeakySeals
Recently purchased the Grand Prix base with a GM 3.8L in my signature. The dash temp gauge has been going over 1/2 towards hot recently, something I'm not used to seeing on my cars. Checking the fluids, I notice Dex-Cool on the expansion tank cap. The coolant doesn't look so hot compared to my OAT running Toyota. "Gelly" and discolored would be the best description. I'm planning a drain and fill.

My questions are:

Should I continue to use Dex-Cool? Have the complaints been resolved/discredited?

Should I/can I use an Asian OAT? I like them, they don;t contain 2-ETHOXYETHANOL. I have a few Gallons of Toyota red on hand. Considering switching to that or something else.

What should I do?


Keep it. I work on cars for a living, the old Dex-Cool problems have been solved, the biggest problem with Dex-Cool years ago was a bad radiator cap that would let air in to the cooling system. It is possible that the Dex-cool in your car is past it's flush date or the prior owner added something to the cooling system. I would also recommend that you have your intake manifold gasket checked before you flush out you cooling system, GM has a big problem with bad intake gaskets on way to many of their V-6 engines, they leak and allow coolant to leak internal into the engine and external at the front and rear of the engine. I have no problem with Dex-Cool aprox 40% of the cars and trucks we service a GM with no Dex-Cool related problems.

 

[lubin it up]

Just replaced original water pump 250,000, and still used dex-cool
I did have tha gasket problem at 152,000 mile and replaced it with the better feel pro
I have never had a problem otherwise.

 

[SteveSRT8]

Originally Posted By: Stu_Rock
Originally Posted By: daves87rs
An 08? Dex should be fine. The later 3.8s didn't have issues with it...
Clearly this one did have an issue with it.

Once a Dexcool system has actually sludged, I see no reason to believe that Dexcool is OK for that particular engine. What is it that they say about insanity and trying the same thing over again?

JHZR2 got lucky with his truck, and given its good record with Dexcool, I think it's perfectly reasonable to continue using it in that particular truck.


While the problems of dex are well documented you will never hear from the millions of happy owners who NEVER had a problem. We have a fleet and have never experienced any dex related issues on any vans or pickups, all GMC.

We now run all fleet trucks to component failure in the cooling systems. And ours have heat exchangers plumbed into them GUARANTEEING air in the system!

Older GM vehicles actually had a gasket issue. Dex is unchanged and still in use. Even Ford is coming over.

 

[oldmaninsc]

I agree with Steve. When I changed the antifreeze on my Trailblazer after 4 1/2 years there was absolutely no signs of sludge or anything else. Everything looked nice and clean - just like JHZR2's truck.

 

[LeakySeals]

Thats clean enough for me. I think this car was a quick lube-er. So they could have mixed some top offs with whatever brand they carry in bulk. Like a chameleon or something. To me it just looks like 70k is enough. Time to change.

 

[LeakySeals]

Which dexcool brand do they carry at Walmart? Would prefer a concentrate over a 50/50 pre-mix if possible.

 

[raaizin]

Originally Posted By: JHZR2
Nothing like the junk that Dex leaves behind inside the original radiator in my 98 Chevy truck - an engine and radiator design not created for Dex...

I agree I put it in my '96 explorer and '02 maxima. I put 211k miles on explorer on original waterpump and rad looked fine when I sold car. We put 162k on our maxima with no issues also.I am still running it in this car

 

[LeakySeals]

Originally Posted By: raaizin
I agree I put it in my '96 explorer and '02 maxima. I put 211k miles on explorer on original waterpump and rad looked fine when I sold car. We put 162k on our maxima with no issues also.I am still running it in this car

Did you drain and fill or flush? How often?

 

[Stu_Rock]

Originally Posted By: Stu_Rock
I advise against using Dex-Cool in systems that don't have pressurized tanks. The constant supply of fresh oxygen just kills that coolant. The 3800 does not have a pressurized tank, so please dump the Dexcool and do a thorough cleaning of the cooling system.
I just found out that the 2008 Grand Prix is the only 3800 application that does actually have a closed cooling system, so I retract what I said. I would consider continuing to run Dexcool in this car if the cooling system cleans up OK.

But I still think all of the steadfast Dexcool apologists are full of it. Those open systems with the garbage metal TVS radiator caps just can't handle it. I know they exist, but I've never personally seen one that didn't have sludge.

 

[SteveSRT8]

Note that while our Silverado fleet trucks have a pressurized coolant bottle the Savanas mostly do not.

Never an issue, and we never touch them until something breaks. This can easily be 200k miles or more.

They are always spanking clean and shiny.

 

[ChrisJH]

I made the (possible) mistake of putting DexCool in the cooling system of my Frontier. I had everything flushed, had to replace the t-stat and its gasket, etc. Went to AZ and grabbed a Prestone product like I normally would.

It wasnt until I had it all back in the radiator when I read about DexCool. The biggest "issue" seems to be in open (non-pressurized) systems, which my Frontier has. Just to be safe, I flushed the Dex out and will be refilling with STP Global (I started another thread on that product)

Is Dex safe? Probably. It just gets me that everyone says to flush DexCool every 2 or 3 yrs anyway. At that point, wouldnt good old conventional green give you the same amount of protection for the same amount of time?

 

[raaizin]

Originally Posted By: LeakySeals
Originally Posted By: raaizin
I agree I put it in my '96 explorer and '02 maxima. I put 211k miles on explorer on original waterpump and rad looked fine when I sold car. We put 162k on our maxima with no issues also.I am still running it in this car

Did you drain and fill or flush? How often?


I drain and flushed till water came out absolutley clear. I changed it every 5 years or so in explorer, but on maxima I neglected it and its been in 6+ years. I plan on doing it when weather cools in Sept/Oct.

 

[Boss302fan]

Dexcool if fine but I always overfill to the hot line in the overflow tank(with engine cool) to make sure there will not be air in the system. I also replace the radiator caps every 2-3 years. Cheap insurance...

The radiators in my 04 Impala SS and my son 03 Monte Carlo SS look like new...

 

[jjcom]

I've got an 07 Grand Prix, that the PO had flushed the dex-cool out of replaced with a universal coolant. I've since done a good flush on it and stayed with Advance brand universal. Never had a problem with it in any cars I've ever worked on, so I figure it's good enough for mine!

Now my 96 Grand Prix, has had Dex-cool in it since new. The first flush came out dirty at 130,000 but it had never been changed before. I now just drain and fill every couple years, it's never gummed up or done anything strange in the time I've had it. I did have to put a radiator in it at alittle over 200,000 miles, but I really can't blame Dex for that. 16 year old, 200,000+ mile plastic radiator developed a hairline crack, but otherwise looked clean when I pulled it out.

I think the moral I'm trying to say is, Dexcool is fine if changed at a decent interval. If you change it out every 2-3 years or 50,000 miles I don't see it causing a problem.

 

[Jim 5]

- 98 Chev k1500 with the 5.7L and leaky LIM issues. No sludge. Coolant changed at 120k miles and 180k miles.

- 04 Chev Avalanche 5.3L no sludge when I sold at 70k miles. Coolant changed at about 60k miles. No sludge - coolant came out looking brand new.

- 07 GMC Sierra 6.6L diesel. I changed the coolant at 48k miles when I replaced a bad block heater. Coolant looked brand new and the insides of the radiator etc looked factory new.

I do not think there is anything wrong with this coolant. If I'm not mistaken, Shell Rotella ELC coolant is basiscally dexcool. Rotella has a repution that they can't afford to mess with. Many other coolants (for cars and motorcycles) are dexcool or dexcool-like as well these days also.

I think this coolant is standing the test of time, notwithstanding GM had at the time of its introduction some issues with cooling architecture, intake manifold torquing and gasket design.

 

[lucerne06]

2006 lucerne 3.8 series III, dex cool since new...everything is fine and clean and shiny, I actually like the dex cool.

 

[Ramblin Fever]

I just find it odd that the fluid must be changed every 2-3yrs; at which point, old true green works just as good. thought the whole point to dex-cool was for an extended life product?

 

[SteveSRT8]

The reason it sounds odd is that info is completely erroneous.

We run a fleet of GM vehicles and routinely run them from brand new to COMPONENT FAILURE in the cooling system. This is generally in excess of 200k miles or much more, regardless of time.

Some are sealed systems, some are not. The radiators are always sparkling clean and shiny, and the heat exchangers are too.

Before Dex it was routine for us to replace water pumps at 100k+ miles. There is a great deal of "Internet amplification" with regards to Dex on this and other forums.