Antifreeze Swap
Thread Starter
Instructor
Joined: Feb 2018
Posts: 103
Likes: 29
Antifreeze Swap
Has anyone done an antifreeze swap on a C5? Getting rid of dexcool and using the green? Just wondering. Anyway,if it was to be swapped, will it cool the same? What are the ups and downs? I know the green is cheaper. If this has been posted somewhere else, sorry in advance for the repost.
Thanks,
Tony
Thanks,
Tony
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Is there any reason why you want to discontinue using the Dexcool? It is a good coolant and was the factory fill since 1995.
Sure the green coolant is cheaper but isn't a really good reason to change. Dexcool will allow you to go up to 5 years between a flush and refill of Dexcool. A green coolant (ethylene glycol) will need changing every two years. Green coolant will work and cool the system; Either coolant should be mixed in a 50% ratio for proper cooling and temp protection.
But to do the swap, you will need to remove all traces of the Dexcool from the cooling system before using any sort of green coolant. This means doing a good flush 3-4 times. IMHO, I think you will be better off by buying the Dexcool and doing a flush and refill. Dex is available as a pre-mix solution, but it will be less costly by buying the concentrated jugs and going to a grocery store and getting a couple gallons of distilled water to mix your own solution.
Sure the green coolant is cheaper but isn't a really good reason to change. Dexcool will allow you to go up to 5 years between a flush and refill of Dexcool. A green coolant (ethylene glycol) will need changing every two years. Green coolant will work and cool the system; Either coolant should be mixed in a 50% ratio for proper cooling and temp protection.
But to do the swap, you will need to remove all traces of the Dexcool from the cooling system before using any sort of green coolant. This means doing a good flush 3-4 times. IMHO, I think you will be better off by buying the Dexcool and doing a flush and refill. Dex is available as a pre-mix solution, but it will be less costly by buying the concentrated jugs and going to a grocery store and getting a couple gallons of distilled water to mix your own solution.
Team Owner
Joined: Jul 2016
Posts: 25,303
Likes: 1,683
From: The Steel City, Colorful Colorado
Winner 2020 C7 of the Year - Modified
Is there any reason why you want to discontinue using the Dexcool? It is a good coolant and was the factory fill since 1995.
Sure the green coolant is cheaper but isn't a really good reason to change. Dexcool will allow you to go up to 5 years between a flush and refill of Dexcool. A green coolant (ethylene glycol) will need changing every two years. Green coolant will work and cool the system; Either coolant should be mixed in a 50% ratio for proper cooling and temp protection.
But to do the swap, you will need to remove all traces of the Dexcool from the cooling system before using any sort of green coolant. This means doing a good flush 3-4 times. IMHO, I think you will be better off by buying the Dexcool and doing a flush and refill. Dex is available as a pre-mix solution, but it will be less costly by buying the concentrated jugs and going to a grocery store and getting a couple gallons of distilled water to mix your own solution.
Sure the green coolant is cheaper but isn't a really good reason to change. Dexcool will allow you to go up to 5 years between a flush and refill of Dexcool. A green coolant (ethylene glycol) will need changing every two years. Green coolant will work and cool the system; Either coolant should be mixed in a 50% ratio for proper cooling and temp protection.
But to do the swap, you will need to remove all traces of the Dexcool from the cooling system before using any sort of green coolant. This means doing a good flush 3-4 times. IMHO, I think you will be better off by buying the Dexcool and doing a flush and refill. Dex is available as a pre-mix solution, but it will be less costly by buying the concentrated jugs and going to a grocery store and getting a couple gallons of distilled water to mix your own solution.
Thread Starter
Instructor
Joined: Feb 2018
Posts: 103
Likes: 29
I had just seen somewhere that dexcool gums up. Don't lnow if it's true or not. I was just wondering what everyone's opinion was on this subject also. I didn't have any plans to swap it unless it was highly recommended to do so. Now my other question is .... What color is dexcool? What color should it be in my radiator fill tank?
Thanks,
Tony
Thanks,
Tony
Racer
Joined: Dec 2002
Posts: 331
Likes: 17
From: Kerrville Texas
If it eases your mind any, I have a 2003 that has had nothing but Dexcool in it from the beginning. Every time I drain it, the Dexcool looks like new and the overflow tank is as clean as the day the car was bought.
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Instructor
Joined: Dec 2017
Posts: 139
Likes: 44
From: Fort Worth, TX
Ah more of the Dexcool sludge rumors. Dexcool does NOT cause sludging or "gumming up" unless one of three things happen:
- The car vastly exceeds it's coolant change interval.
- It is mixed with conventional green coolant.
- It is exposed to a lot of air because of a leaky cooling system.
Burning Brakes
Joined: Jan 2006
Posts: 788
Likes: 105
From: Olathe Kansas
Just drain out as much as you can Refill with mixture of the UNIVERSAL LONG LIFE Coolant.. It mixes ok with DexCool..
Just NEVER run the old old old school green stuff-- it's even hard to find so you should
be able to avoid it.
I personally keep dexcool in GM's and the Universal in all the other makes. That way I only have to carry 2 kinds in stock.
Just NEVER run the old old old school green stuff-- it's even hard to find so you should
be able to avoid it.
I personally keep dexcool in GM's and the Universal in all the other makes. That way I only have to carry 2 kinds in stock.
Thread Starter
Instructor
Joined: Feb 2018
Posts: 103
Likes: 29
Reservoir coolant looks brown to me not orange. Maybe it is an old orange ..... lol. Car has 36k on odometer. I know it has dexcool in it. I guess I could do a complete flush and refill with dexcool. It would seem like that this would be the best thing to do.
Thanks,
Tony
Thanks,
Tony
8th Gear
Joined: Feb 2018
Posts: 8
Likes: 0
From: Manchester Md
Reservoir coolant looks brown to me not orange. Maybe it is an old orange ..... lol. Car has 36k on odometer. I know it has dexcool in it. I guess I could do a complete flush and refill with dexcool. It would seem like that this would be the best thing to do.
Thanks,
Tony
Thanks,
Tony
Thread Starter
Instructor
Joined: Feb 2018
Posts: 103
Likes: 29
I rechecked my coolant today and it looked good. I guess it looked dark to me. I couldn't really tell the color in the dark even with a flashlight. Things always look different at night don't they. Anyway, I did a complete brake and rotor job and changed the oil and filter today. Moving on to other stuff now...
Thanks to all,
Tony
Thanks to all,
Tony
Racer
Joined: Dec 2002
Posts: 331
Likes: 17
From: Kerrville Texas
RO water is pretty pure, but I would err on the side of going with distilled water. Besides, they have a 50/50 mix of Dexcool in gallons ready to go. That's what I usually do. Much easier than mixing myself.
Pro
Joined: Sep 2013
Posts: 512
Likes: 10
Advanced
Joined: Apr 2016
Posts: 89
Likes: 22
From: Forest, VA
tonyclark1:
Recheck your antifreeze. How long has it been since your car was flushed/refilled? If you don't know, do it!
Miles and/or time degrades all antifreeze solutions.
Yes, Dex-Cool has had a checkered reputation with regard to sludge which some claim contributed to intake manifold and head gasket failures on other GM vehicles (primarily 3.1 & 3.4 V6s and late 1990s Northstar V8s). However, I'm not sure that it was the fault of the Dex; I believe that it was poor or no maintenance by the owners.
When Dex gets old it does form a brown sludge which can be first found in the "overflow" reservoirs.
Stick your fingers into the reservoir and feel around the inside top around the opening. If it's brown; flush it down! Refill with fresh Dex or the universal that foggy mentioned.
Our Corvettes are our toys. Treat it with great respect.
Recheck your antifreeze. How long has it been since your car was flushed/refilled? If you don't know, do it!
Miles and/or time degrades all antifreeze solutions.
Yes, Dex-Cool has had a checkered reputation with regard to sludge which some claim contributed to intake manifold and head gasket failures on other GM vehicles (primarily 3.1 & 3.4 V6s and late 1990s Northstar V8s). However, I'm not sure that it was the fault of the Dex; I believe that it was poor or no maintenance by the owners.
When Dex gets old it does form a brown sludge which can be first found in the "overflow" reservoirs.
Stick your fingers into the reservoir and feel around the inside top around the opening. If it's brown; flush it down! Refill with fresh Dex or the universal that foggy mentioned.
Our Corvettes are our toys. Treat it with great respect.
Tech Contributor
Joined: Oct 1999
Posts: 41,043
Likes: 9,807
From: Charlotte, NC (formerly Endicott, NY)
I had just seen somewhere that dexcool gums up. Don't lnow if it's true or not. I was just wondering what everyone's opinion was on this subject also. I didn't have any plans to swap it unless it was highly recommended to do so. Now my other question is .... What color is dexcool? What color should it be in my radiator fill tank?
Thanks,
Tony
Thanks,
Tony
Dex is orange and remains orange during its 5 year life cycle and longer. I have gone through multiple 5 year changes on my 2003 Tahoe and am getting ready to change the Dex again this year. The cooling system consists of all of the original parts that were delivered on the vehicle. The only thing that changed was the coolant every 5 years. I have also changed the Dex on several other vehicles after 5 years and found it to retain its original color throughout the time period. The last time I used the Green Crap in a vehicle was 25 years ago.
You don't need to change it for 5 years but once you reach 5 years get it changed within a few months after that.
Bill
Racer
Joined: Feb 2018
Posts: 252
Likes: 21
From: Meridian Idaho
You can go to research why engineers make changes on what might seem to be a small thing, Im sure you will come to the same conclusion that the change was warranted, flush every few years is a small investment toward keeping a greatly engineerd car ready for whatever you have it for.
Acct Suspended APR 2026 by request
Joined: Dec 2010
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2020 Corvette of the Year Finalist (performance mods)
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I agree with some of the posters above, as long as you keep it fresh and don't mix it with whatever you could find at the time dexcool works great... I always buy the unmixed bottles of delco brand dex because you can mix them yourself and get 2 gallons out of it instead of 1 gallon of the stuff that is already mixed and it costs about the same price, maybe a tad more... I always use a 50/50 mix with distilled water as well