: Convert from Dex-Cool to green antifreeze



boston636
05-03-11, 10:14 PM
I wanted to change the antifreeze but was only able to drain ~1 gallon of DexCool from my 2004 DTS. Before I knew mixing different types of antifreeze causes sledge, I refilled with 50/50 green antifreeze. Now I want to flush out the entire contaminated cooling system, but don't know how. Can someone please offer advice.

johnnyjaws
05-17-11, 11:21 AM
start car get garden hose and open the radeator put hose in it open bottom valve on raditor turn heat on high turn on hose and flush system till it runs clean

vincentm
05-18-11, 12:11 AM
Does GM specify the use of Dex for your particular vehicle? If so, id stick to that

-------------------------------------------------------
Sent from my Northstar powered phone

ThumperPup
05-19-11, 08:16 AM
Does GM specify the use of Dex for your particular vehicle? If so, id stick to that

-------------------------------------------------------
Sent from my Northstar powered phone

alot of us don't like dex and some of us do
just because GM spec's to you Dex does not mean its the best
are you truly going to go the 100k or 150k what ever it is before changing ?
Jake doesn't use Dex i think he acutaly swears against it or osmething like that
Green is better in some of our apinions only reason i have Dex right now is cause its what the Mechanic put in
i forgot to tell him go green not pink when rebuilding the engine
but going to wait to put green in till i replace the heater core

Ranger
05-19-11, 12:27 PM
Before I knew mixing different types of antifreeze causes sledge
I've mixed the two in a bucket and never saw any "sludge", but they do say not to mix them so you need to flush it as advised. It would have been a lot easier if you just left the factory coolant in there. Nothing wrong with Dex.

vincentm
05-19-11, 01:36 PM
alot of us don't like dex and some of us do
just because GM spec's to you Dex does not mean its the best

When it comes to this particular thing, i think you need to give GM a bit more credit. even with a HG issue ive ran the DEX after having it flushed and never seen it cause an issue, nor did my ride ever overheat.


are you truly going to go the 100k or 150k what ever it is before changing ?

Got my ride @ 126k, had it flushed, oil change, tune up, and out another 6k on it before i had it sent off to CCC. And even up to that point, it still never overheated, no smoke, zilch, but i still knew i had a bad HG because of the block test it failed months back. I just happened to nip it in the bud before i got stranded somewhere.



Jake doesn't use Dex i think he acutaly swears against it or osmething like that
Green is better in some of our apinions only reason i have Dex right now is cause its what the Mechanic put in
i forgot to tell him go green not pink when rebuilding the engine
but going to wait to put green in till i replace the heater core

The main ingredient in DEX is the Ethylene Glycol that is suspect to cause the deterioration in the gaskets, but its a chicken/egg thing with this issue, pulled bolts vs Dex

Ranger
05-19-11, 02:43 PM
The main ingredient in green coolant (any coolant for that matter) is Ethylene Glycol as well. Same as Dex.

ThumperPup
05-19-11, 04:53 PM
i don't like dex i have heard that it eats away at the gaskets
my first hg problem was actualy the gasket if im corect joe said that the thread did not come out when he took the head bolts out
the first time they didn't want to come out to easy but they did not pull the threading with them for me it was the gasket issue and
from the car fax i could tell it only had one coolant service doen and that was at 50k when the car was 7 years old
so excuse me if im no fan of dex
yeah its also the part that i don't think any coolant lasts that long i think it should be changed atleast every 2 or 3 years
and i probalby won't buy a car with another N unless it can be proven that its had the proper cooling system services when it should and not just when ppl think that its ok to take a dex filled car and not service it till it has 100k on it even if thats 12 years latter

so yes majority is failed head bolts but for me it was gasket and probably a combo of the dex and not being services properly

yea green needs to be services even more but i feel its better just an apinion
if you do it when you should then it will last we all know this or atleast it should

vincentm
05-19-11, 05:19 PM
i don't like dex i have heard that it eats away at the gaskets
my first hg problem was actualy the gasket if im corect joe said that the thread did not come out when he took the head bolts out
the first time they didn't want to come out to easy but they did not pull the threading with them for me it was the gasket issue and
from the car fax i could tell it only had one coolant service doen and that was at 50k when the car was 7 years old
so excuse me if im no fan of dex



Dude read what you just posted here, 7 yrs without changing coolant and you blame the Dex?



yeah its also the part that i don't think any coolant lasts that long i think it should be changed atleast every 2 or 3 years
and i probalby won't buy a car with another N unless it can be proven that its had the proper cooling system services when it should and not just when ppl think that its ok to take a dex filled car and not service it till it has 100k on it even if thats 12 years latter

Read what i said above.


so yes majority is failed head bolts but for me it was gasket and probably a combo of the dex and not being services properly

yea green needs to be services even more but i feel its better just an apinion
if you do it when you should then it will last we all know this or atleast it should

Sorry to take this off track but your posts are hard to read some times, i suggest taking more time on them and using proper grammar and punctuation.

ThumperPup
05-19-11, 05:23 PM
ok well still id rather put green in and chang every 50k wich is 16 to 18 months
than do dext and go the 100k recomended

ktuckjr
11-20-11, 08:32 AM
I've mixed the two in a bucket and never saw any "sludge", but they do say not to mix them so you need to flush it as advised. It would have been a lot easier if you just left the factory coolant in there. Nothing wrong with Dex.

Dex sucks..str8 up...GM used it to make money in the future. When you mix it in a bucket it is not gonna do any thing....it is corrosion not sludge. Your block is grounded to the fram and battery...so your coolent is in the block and it is a cunductor. Its not mixing them that causes corrosion its the the reaction that happens when it has current going through it.
BAMM

ktuckjr
11-20-11, 08:36 AM
It is called electrolysis

Submariner409
11-20-11, 09:37 AM
Both posts #11 and #12 contain incorrect information.

Every car body - and engine - rides on the negative side of the DC electrical system, so the "engine grounded to the frame" theory is false. (There were 1940's cars with positive ground systems, but that went away in a hurry.)

Electrolysis occurs when two dissimilar metals are immersed in an electrolyte - so one would think that, if the electrolysis theory was correct, every ferrous bolt in every aluminum block engine in the world would eventually rot out. I don't believe that has happened to date. Yes, electrolysis is an electrical phenomenon - but it doesn't apply to the Northstar - or any other aluminum engine. (Consider that the cast iron cylinders are cast into the aluminum block, for starters...............)

Ethylene glycol is not an electrolyte as such - the reason you change it every few years is due to the depletion of the anti-foam and anti-corrosion package.

Bottom line: Run whatever coolant you like - just change it every two or three years. How about this to cloud the issue: Look at some of the new road hauler cooling system "Heavy Duty" coolants - a different additive package than either DEX-COOL or Green Goddess. We use it in marine sealed cooling systems.

Ranger
11-20-11, 12:20 PM
Where do people come up with these theories? :bigroll:

Submariner409
11-20-11, 03:28 PM
Where do people come up with these theories? :bigroll:

From Forums similar to "BobIsTheOilGuy" - people fail to read between the lines of opinion and hearsay.

drewsdeville
11-20-11, 07:25 PM
FWIW, with a little basic testing, I've found that Dex loses it's anti-corrosive properties around 5-6 years in worst case scenarios. I maintain an aluminum blocked 1989 Cadillac with Dex that's coming up on it's 10th year, and it still tests fine.and looks perfectly clean (though it will be changed next year)...

I personally believe that the 2-3 year interval for changing Dex is quite light, but to each their own.

The Noel
12-02-11, 11:33 AM
What about using the Mercedes Benz factoy coolant. I didn't play around when I have my 1996 S600 V12. I also used it in my 1989 Chrysler Lebaron Turbo which is notorious for blowing head gaskets, and that never got hot 20,000 miles later and driving it hard. My 89 Saab 900 conv. Turbo that I saved from the crusher. I also use it in my 1986 Chrysler Laser with 310 hp, and large turbo. Here is an article: http://www.thesaabsite.com/Coolantinfo.htm

The Noel
12-02-11, 11:54 AM
IMO if you are gona use "The Green S#@T" I would flush it out every year especially on the Northstar.

Submariner409
12-02-11, 03:47 PM
No need to change good ol' green coolant or DEX-COOL every 1 - 2 years. Both have an additive package sufficient to go 3 years, and that's the frequency at which it should be changed.

There's been an awful lot of "green S#@T" used since it took over from alcohol-based antifreeze formulas 60-odd years ago.

kildysartkid
12-06-11, 10:37 PM
If the Dex coolant was the root cause of HG failures, why then has there been much less HG issues with 2005 and newer Northstars that have the new style head bolts but still use Dex coolant.
Having said that, when I did replace head gaskets on my 2000 Deville, the bolts were all tight but the gaskets were really rotted out.

Mark D
12-07-11, 04:07 PM
Believe it or not, it also helps a lot to use distilled water. Flush it with distilled water and continue to use distilled water with the antifreeze of your choice
Mark D.

maeng9981
12-07-11, 04:35 PM
Believe it or not, it also helps a lot to use distilled water. Flush it with distilled water and continue to use distilled water with the antifreeze of your choice
Mark D.

You are supposed to use distilled water when you mix a coolant - tap water has minerals that might cause the corrosion inhibitors to degrade and might be able to produce deposits.