Dex-Cool - keep it or swap it?

[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?

 

[rshaw125]

I have this engine in a Buick. 3800 series III. Get rid of the Dex-cool. The coolant in my Buick was the worst I have ever seen. Sludge.
I drained it thoroughly,flushed it through with water from the hose and then ran distilled water in it for a few miles. Drained it again. Cleaned the over flow bottle which was nasty.
Refilled with 50/50 distilled water and Peak Global lifetime. I will probably do it again next summer.
Get rid of the Dex-cool.

 

[JHZR2]

never had sludge in my 98 truck which has the 4.3.

Swap it and do it often. Dex cool isnt forever, no cooling system should have air in it, and no green should be mixed.

 

[SEMI_287]

Get rid of it. My overflow bottle on my Grand Am was sludgy.

 

[heyu]

Change it and switch away from Dex Cool ,,Ive had my share of replacing a few head gaskets, intake gaskets ,water pumps and the Dex Cool just eats up the metal inside a motor after awhile

This situation never happened any other anti freeze /coolant until Dex Cool came out

 

[NHGUY]

If I had a GM product (never again),the Dex Cool would be out faster than you can blink an eye,and green or Global Ford/Chrysler would be in it.

 

[Chris B.]

I read on here several years back the DEX Cool was good to go and did not cause problems at all if changed every 2 or 3 years. I have owned many 1990's vintage GM cars and trucks and still own a 1997 Sierra and never had a single Dex cool related problem but I flush it every few years. In fact my 1997 SIerra still has it's original radiator and not a hint of any build up or sludge.

 

[ChrisJH]

Originally Posted By: Chris B.
I read on here several years back the DEX Cool was good to go and did not cause problems at all if changed every 2 or 3 years. I have owned many 1990's vintage GM cars and trucks and still own a 1997 Sierra and never had a single Dex cool related problem but I flush it every few years. In fact my 1997 SIerra still has it's original radiator and not a hint of any build up or sludge.



Ive read that too, but I thought the whole point of DexCool was to help extend the time between flushes.

Is that like the synth vs dino oil debate? No sense using synth if you are going to change it every 3K miles....is there sense in using extended life coolant (with possibly nasty ingredients) just to change it ever 3 years?

 

[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 don't know for sure if the 2EHA is what causes the problems, but I think it's sensible to avoid it. The 3800 seems to respond just fine to everything but Dexcool, so I'd run the Toyota stuff if I had a stash of it. Otherwise, Peak Global or G-05.

 

[oggb]

Not certain on this but I think some GM vehicles don't run the main radiator fan on high until a certain absurdly high (to me) temperature is reached - 220F sounds correct to me. Before that temperature the fan really just creates a slight amount of airflow. Yours may not be one of the models that does this.

See if you can find any info relating to when the main cooling fan operates. This may be normal.

If, however, this behavior has just begun - you need to flush the cooling system. Whether or not you replace it with Dex-Cool is up to you, but if you find large amounts of sludge in the radiator I certainly wouldn't do it.

 

[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...

 

[daves87rs]

An 08? Dex should be fine. The later 3.8s didn't have issues with it...

If you're that worried, run some Zerex....

 

[LeakySeals]

That looks like what I'm seeing stuck to the walls of the plastic expansion tank. You can see where the hot and cold expansion level is, has a gel-like red/purple-ish goo line. My old Toyota running Red doesn't do anything like that. But I never let it go past 50k. The GP has 70k on it now, doubt its ever been changed.

 

[LeakySeals]

Originally Posted By: JRed
Not certain on this but I think some GM vehicles don't run the main radiator fan on high until a certain absurdly high (to me) temperature is reached - 220F sounds correct to me. Before that temperature the fan really just creates a slight amount of airflow. Yours may not be one of the models that does this.

See if you can find any info relating to when the main cooling fan operates. This may be normal.

If, however, this behavior has just begun - you need to flush the cooling system. Whether or not you replace it with Dex-Cool is up to you, but if you find large amounts of sludge in the radiator I certainly wouldn't do it.

It is running hotter, but its been hot recently and the car is new to me, so I suppose there isn't enough to go by yet. Just that nasty expansion tank with big Dex-Cool lettering on it. If I change will try to scrape it off.

 

[LeakySeals]

Looking at the differences between Dex-Cool OAT and an the Asian Toyota Red OAT I have plenty of:

Dex-Cool:
Ethylene Glycol 80-97%
Diethylene glycol 1-5%
Potassium 2-ethylhexanoate 1-5%

Toyota Red
Ethylene Glycol 87-95%
Diethylene glycol Hydrated inorganic acid, organic acid salts
Asian coolants don't use 2-ethylhexanoate (2-EHA). Its the only difference, so 2-EHA must be the source of the supposed problem. I dont see a reason why Toyota red can't be used, anyone else? I'm just going to do a few drain and fills over the next 20k, don't see a need to go through the flush. Sound ok?

 

[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.

 

[dave1251]

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...

This is more common than the death cool stories. Maybe the members that got torched are the few that got touched by GM's outstanding QC.

 

[Donald]

Originally Posted By: LeakySeals
Looking at the differences between Dex-Cool OAT and an the Asian Toyota Red OAT I have plenty of:

Dex-Cool:
Ethylene Glycol 80-97%
Diethylene glycol 1-5%
Potassium 2-ethylhexanoate 1-5%

Toyota Red
Ethylene Glycol 87-95%
Diethylene glycol Hydrated inorganic acid, organic acid salts
Asian coolants don't use 2-ethylhexanoate (2-EHA). Its the only difference, so 2-EHA must be the source of the supposed problem. I dont see a reason why Toyota red can't be used, anyone else? I'm just going to do a few drain and fills over the next 20k, don't see a need to go through the flush. Sound ok?


I don't think its as black and white as that to pin point the 2-EHA. Don't they also have some proprietary additives also?

But given the looks of your tank, go to G-05.

 

[daves87rs]

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.


Well, that could be debated, as we do not know how it was cared for before he got it. For all we know, the GP could have spent it's early life delivering pizza for 12 hours..you never know.

I have 3 cars with dex in them-and they all still look good...

 

[ChrisD46]

2005 Buick Century - Use DexCool and change every two years , no sludge , no discoloration , no goo , film , etc. Overflow tank is clean too .