Dexcool Bad?
Race Director
Joined: Oct 2000
Posts: 11,891
Likes: 3
From: Kansas City, MO ...I'd like to go fishing and catch a fishstick. That'd be convenient. - Mitch Hedberg
Dexcool isn't all bad. However, the green and the orange can NEVER mix. They will crystalize if they do. To switch from one to the other, they cooling system must be flushed and cleaned or you are looking for long term trouble.
However, it has been a major cause of headaches in my '96 Chevy p/u. The dexcool was known to degrade the gaskets it is in contact with. I've been told that the gasket material has been adjusted accordingly, but I don't believe it. I've changed my water pump gaskets and intake manifold gaskets twice each in 145k miles. Now, the more important question, why am I still using it? I have no idea. Guess I never thought I'd still own the truck after 9 years.
I've also read that flushing and refilling the system will reduce the effect on gaskets. Still haven't seen much proof of that. Of course, everyone has a different opinion and experience with the stuff.
However, it has been a major cause of headaches in my '96 Chevy p/u. The dexcool was known to degrade the gaskets it is in contact with. I've been told that the gasket material has been adjusted accordingly, but I don't believe it. I've changed my water pump gaskets and intake manifold gaskets twice each in 145k miles. Now, the more important question, why am I still using it? I have no idea. Guess I never thought I'd still own the truck after 9 years.
I've also read that flushing and refilling the system will reduce the effect on gaskets. Still haven't seen much proof of that. Of course, everyone has a different opinion and experience with the stuff.
Safety Car
Joined: Aug 2000
Posts: 3,943
Likes: 44
From: Florham Park NJ Port Credit Ontario
I had a 98 blazer that only was serviced by the dealership. By 2001 the cooling system was so clogged by sediment that the entire system was replaced by GM. Many claim that the dexcool was the problem. It wasnt admitted by the dealership however, when I began litigations against GM under Ohio Lemon Law, they settled out of court almost immediately.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
PERZACTLY, the green ethelyn glycol has worked for decades in aluminum, iron.copper, brass, rubber, ***, whatever....
why change??? NO GOOD REASON....
must be an EPA thing.....much adoo/nonsense over nothing....
something about 1 part per brazillion in the rivers.....meaningless....
Burning Brakes
Joined: Feb 2005
Posts: 1,235
Likes: 0
From: Mesa AZ
PERZACTLY, the green ethelyn glycol has worked for decades in aluminum, iron.copper, brass, rubber, ***, whatever....
why change??? NO GOOD REASON....
must be an EPA thing.....much adoo/nonsense over nothing....
something about 1 part per brazillion in the rivers.....meaningless....
why change??? NO GOOD REASON....
must be an EPA thing.....much adoo/nonsense over nothing....
something about 1 part per brazillion in the rivers.....meaningless....
they didn't even have dexcool when they came out with aluminum radiators. so why change to a different coolant now?
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
I say if you WANT to trash your radiator, heater core, freeze plugs, and gaskets...then by all means use Dex. As a bonus, it'll clog everything up good and gooey like. Go for it.
If you want a clean system, that works as it should, use green, or Preston's new Yellow.
If you want a clean system, that works as it should, use green, or Preston's new Yellow.
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Thread Starter
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
At the time I switched the 5 year life appealed to me 
I have run green for the first 20 years and the
2 year change out came faster and faster (age
)
I thought hey 5 years Kool.
The Internet has made me smile, taught me stuff, and
made worry about OIL, Filters, Gas and now coolant.
Ain't it great ?
thanks for your experiences and thoughts
I have run green for the first 20 years and the
2 year change out came faster and faster (age
)I thought hey 5 years Kool.
The Internet has made me smile, taught me stuff, and
made worry about OIL, Filters, Gas and now coolant.
Ain't it great ?
thanks for your experiences and thoughts
Melting Slicks
Joined: May 1999
Posts: 2,897
Likes: 0
From: Moon Township PA
PERZACTLY, the green ethelyn glycol has worked for decades in aluminum, iron.copper, brass, rubber, ***, whatever....
why change??? NO GOOD REASON....
must be an EPA thing.....much adoo/nonsense over nothing....
something about 1 part per brazillion in the rivers.....meaningless....
why change??? NO GOOD REASON....
must be an EPA thing.....much adoo/nonsense over nothing....
something about 1 part per brazillion in the rivers.....meaningless....
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Drifting
Joined: Aug 2004
Posts: 1,677
Likes: 1
From: Potomac Falls VA
At the time I switched the 5 year life appealed to me
I have run green for the first 20 years and the
2 year change out came faster and faster (age )
I thought hey 5 years Kool.
The Internet has made me smile, taught me stuff, and
made worry about OIL, Filters, Gas and now coolant.
Ain't it great ?
thanks for your experiences and thoughts
I have run green for the first 20 years and the
2 year change out came faster and faster (age
)I thought hey 5 years Kool.
The Internet has made me smile, taught me stuff, and
made worry about OIL, Filters, Gas and now coolant.
Ain't it great ?
thanks for your experiences and thoughts
Now I am paranoid as well! I was about to replace some hoses and therefore have to refill my coolling system with 50/50 dexcool and distilled water but now I am thinking that is a BAD idea. So how extensively would I have to flush my system (and how) to switch cooants?
Shane
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Completely.
Completely drain the system by draining the rad and pulling the water jacket plugs in the sides of the block. Get all the coolant out and dispose of it.
The quick and easy way to flush is a water hose. Remove the upper and lower radiator hoses, and start by flushing garden hose water into the upper rad hose. Stuff a rag in around it so you have good pressure and let it go until the fluid coming out the bottom rad hose is clear. Do the same for the radiator.
Then button it all up, and fill with a 50/50 mixture of the new fluid of your choice.
Burning Brakes
Joined: Oct 2004
Posts: 763
Likes: 0
From: Loveland Colo
If I may interject once again about home-flushing the coolant:
It's a real biatch to disconnect the bottom hose, but why bother anyway? Use 3/8" or larger piece of rubber oil line at least 6' long and siphon the radiator.
Drain the block, siphon the rad, fill it back up with water, run the engine till it starts circulating, and then just siphon and top off continuously while the engine is running and circulating, until the water is clear in the bucket. Do this till you're comfortable the system is flushed.
Then, in my opinion, drain the block and rad again, and fill with Zerex GO5 and distilled water.
And, again, to get the siphon going, wrap rag around the hose at the filler neck and BLOW through it to pressure up the rad to start the siphon.
John
It's a real biatch to disconnect the bottom hose, but why bother anyway? Use 3/8" or larger piece of rubber oil line at least 6' long and siphon the radiator.
Drain the block, siphon the rad, fill it back up with water, run the engine till it starts circulating, and then just siphon and top off continuously while the engine is running and circulating, until the water is clear in the bucket. Do this till you're comfortable the system is flushed.
Then, in my opinion, drain the block and rad again, and fill with Zerex GO5 and distilled water.
And, again, to get the siphon going, wrap rag around the hose at the filler neck and BLOW through it to pressure up the rad to start the siphon.
John
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
There is a great mental image associated with this tip...which I love, and I would really like to see Photovette1 doing a how too video with his models, and siphoning out the radiator fluid. I wan to see closeups of her blowing first to pressurize the radiator.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Le Mans Master
Joined: Jan 2007
Posts: 7,892
Likes: 3,284
From: Omaha NE
2025 c3 ('74-'82) of the Year Finalist - Unmodified
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Prestone only for 30 years. Radiator looks great inside....
Thread Starter
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
I looked at my coolant container closer...........
Havoline Ext Life 5 year (orange)
Dexcool GM approved.
Is this Dexcool? Or Did I escape...............
Havoline Ext Life 5 year (orange)
Dexcool GM approved.
Is this Dexcool? Or Did I escape...............