Coolant Flush After Seeing Gunk?

[90sbuickrescue]

If you type in "deionized water corrosion" on google, this is what comes up with their AI garbage.

Yes, deionized (DI) water is considered corrosive, often called "hungry water," because its lack of ions makes it highly reactive, seeking to dissolve minerals from anything it contacts, like metals (copper, steel), to rebalance itself, leading to issues in plumbing and electronics, especially with long-term contact or exposure to air. While pure water itself isn't a strong acid, it readily absorbs atmospheric carbon dioxide (CO2), forming carbonic acid (H₂CO₃), which slightly lowers its pH and increases its corrosive potential, making it damaging to certain materials over time, notes university research, a university chemistry resource, and a university chemistry website.

Anyway, I wouldn't pour deionized water into any kind of cooling system, just to err on the side of caution. It's not produced by ion exchange like soft water, which leaves the tds or EC high while switching what is actually dissolved in the water, it's the last stage on a reverse osmosis system, that gets out the very last bit of anything that makes the water electrically conductive. I don't really know how it works, I just know it's some kind of resin the water goes through, that you have to replace. I have the DI stage on my system and it does work and produce 0 ppm water, but I never use it.

 

[BuickGirlFromMars]

GM premix is deionized

 

[DrivenDaily]

Interesting that they specifically call for de-ionized water and specifically exclude distilled water.

No matter if the coolant mixture is for the ICE (internal combustion engine, the DHS group) or any of the other components including the EV battery cooler, it is required to use only de-ionized water if mixing it yourself.

So, then, what does that say for older vehicles? Even in my 2011 Malibu V6 I used tap water to top off the cooling system after adding full-strength coolant.

I have since bought distilled water and still have several gallons.

My whole-house water softener uses an ion-exchange process to soften the water. The ions come from salt pellets, but the water has no salt dissolved in it.

My RO (reverse osmosis) drinking water passes the softened water through a membrane with holes so small that only water molecules can pass. It is so pure that when there is a BWA (boil water alert) I am able to drink the RO water without fear of infection, so I do not have to boil my water during these alerts.

How does one find or create de-ionized water?

Can I use softened water or RO water to top off my coolant?

 

[2000ltd]

I always use distilled water and have never had a problem

 

[BuickGirlFromMars]

Interesting that they specifically call for de-ionized water and specifically exclude distilled water.

No matter if the coolant mixture is for the ICE (internal combustion engine, the DHS group) or any of the other components including the EV battery cooler, it is required to use only de-ionized water if mixing it yourself.

So, then, what does that say for older vehicles? Even in my 2011 Malibu V6 I used tap water to top off the cooling system after adding full-strength coolant.

I have since bought distilled water and still have several gallons.

My whole-house water softener uses an ion-exchange process to soften the water. The ions come from salt pellets, but the water has no salt dissolved in it.

My RO (reverse osmosis) drinking water passes the softened water through a membrane with holes so small that only water molecules can pass. It is so pure that when there is a BWA (boil water alert) I am able to drink the RO water without fear of infection, so I do not have to boil my water during these alerts.

How does one find or create de-ionized water?

Can I use softened water or RO water to top off my coolant?

For battery cooling they are trying to limit conductive substances and probably relying on the deionized aspect for corrosion purposes. Since the materials and temps in the battery system won’t be the same as the engine.

 

[BuickGirlFromMars]

How does one find or create de-ionized water?

Can I use softened water or RO water to top off my coolant?

Go to Walmart or grocery store and buy the jugs next to the distilled

I would not use softened water in your system.

Distilled water is fine for the car cooling system in our vehicles. Preferable to tap or softened water.

Deionized water is also fine but just make sure your 50/50% is actually 50%

 

[90sbuickrescue]

DrivenDaily, I believe a water softener's ion exchange is swapping calcium and magnesium for sodium and potassium, 2 "softer" ions. But table salt is sodium chloride, so if your water has sodium ions in it, to me that is still "salt", myself, I wouldn't put that in a cooling system. Those ions do show up on a tds/ec (total dissolved solids/electrical conductivity) meter, which measures the electrical conductivity of the water. Way I see it, just because it won't leave crud on your faucets, shower head, etc doesn't mean it won't facilitate corrosion, since 2 dissimilar metals in an electrically conductive solution creates a battery.

More on EC/TDS, have you measured your reverse osmosis water to see what it actually is? Without doing that, you won't know. If your incoming tap water is 6 or 700, maybe even 800 ppm, when that system starts putting out water, it'll be high at first, say 400 or 500, and then slowly drop down, over maybe a minute or so. A typical drinking water system that fills a pressurized tank will put a lot of high tds water into that tank, since it's always short cycling. A good system will drop it down into the single digits, like 4 ppm. The membrane actually does not allow only water molecules to pass though, it's pressure difference dependent. There is a calibrated restrictor on the bypass side, that creates a certain pressure drop. I can't remember exactly how this is set up, but I know when I went from a 75gpd to a 100 gpd membrane, I could not figure out why my tds wouldn't drop below 20 or 30 or so. Initially I suspected my new membrane was somehow bad, or that my input water pressure was too high, but I eventually learned that I needed a higher flow restrictor on the waste water side to match the higher flow membrane.

After thinking a little more about the DI water thing, it actually sort of makes sense why they would recommend that with their coolant. Since of course once it's mixed in with coolant, it's no longer DI anymore, if their mix has anything in it that makes it electrically conductive. I guess whatever they mix into it has the ability to inhibit corrosion, although I don't know how. I've heard of coolants described as "organic acid technology", which seems weird to me, like you'd want any kind of acid in your cooling system. ? To me it's more intuitive that you can have the coolant be somewhat electrically conductive if it is a base, or higher than 7 on the pH scale, because bases don't dissolve metal like acids. I just googled it and the general consensus seems to be that coolants are always basic, despite being made up of different chemicals or additives. I supposed I could measure it myself with my old hanna 98129 ec/tds/pH meter, but I doubt the pH probe is still good, after sitting for so long.

 

[90sbuickrescue]

Deionized water has the risk of introducing and promoting microbial growth esp with regards to dexcool type coolants

I suppose this depends on how the DI water was made. If it were made in a way that did not remove any of the stuff that doesn't form an ionic solution, then then it could still have who knows what dissolved in it. But with other methods to purify the water first, like reverse osmosis, distillation, etc, and then running it through the DI stage, it should not be able to support the growth of anything at all.

I'm always amazed at how with only 4 or 5 parts per million total dissolved solids, after a while my clear glass drinking water container will start to show green algae growing in it. For reference, most guys growing with deep water culture, near harvest are pushing 1000 ppm. In other words, the drinking water has .0005 the "fertilizer" content of the hydroponic solution, yet it is still able to grow algae.

 

[02LTD2.0]

I agree with @2000ltd and will use distilled water when I do my cooling system maintenance once the weather warms up in the Spring. Thank goodness we have a little less than 2 months to go.

 

[BuickGirlFromMars]

I suppose this depends on how the DI water was made. If it were made in a way that did not remove any of the stuff that doesn't form an ionic solution, then then it could still have who knows what dissolved in it. But with other methods to purify the water first, like reverse osmosis, distillation, etc, and then running it through the DI stage, it should not be able to support the growth of anything at all.

I'm always amazed at how with only 4 or 5 parts per million total dissolved solids, after a while my clear glass drinking water container will start to show green algae growing in it. For reference, most guys growing with deep water culture, near harvest are pushing 1000 ppm. In other words, the drinking water has .0005 the "fertilizer" content of the hydroponic solution, yet it is still able to grow algae.

algae im pretty sure can be exacerbated with certain compounds in water but it ultimately isnt likely to NOT grow because its pure water, im pretty sure just being open and exposed the water is collecting organic matter and microbial species lol

 

[BuickGirlFromMars]

DrivenDaily, I believe a water softener's ion exchange is swapping calcium and magnesium for sodium and potassium, 2 "softer" ions. But table salt is sodium chloride, so if your water has sodium ions in it, to me that is still "salt", myself, I wouldn't put that in a cooling system. Those ions do show up on a tds/ec (total dissolved solids/electrical conductivity) meter, which measures the electrical conductivity of the water. Way I see it, just because it won't leave crud on your faucets, shower head, etc doesn't mean it won't facilitate corrosion, since 2 dissimilar metals in an electrically conductive solution creates a battery.

More on EC/TDS, have you measured your reverse osmosis water to see what it actually is? Without doing that, you won't know. If your incoming tap water is 6 or 700, maybe even 800 ppm, when that system starts putting out water, it'll be high at first, say 400 or 500, and then slowly drop down, over maybe a minute or so. A typical drinking water system that fills a pressurized tank will put a lot of high tds water into that tank, since it's always short cycling. A good system will drop it down into the single digits, like 4 ppm. The membrane actually does not allow only water molecules to pass though, it's pressure difference dependent. There is a calibrated restrictor on the bypass side, that creates a certain pressure drop. I can't remember exactly how this is set up, but I know when I went from a 75gpd to a 100 gpd membrane, I could not figure out why my tds wouldn't drop below 20 or 30 or so. Initially I suspected my new membrane was somehow bad, or that my input water pressure was too high, but I eventually learned that I needed a higher flow restrictor on the waste water side to match the higher flow membrane.

After thinking a little more about the DI water thing, it actually sort of makes sense why they would recommend that with their coolant. Since of course once it's mixed in with coolant, it's no longer DI anymore, if their mix has anything in it that makes it electrically conductive. I guess whatever they mix into it has the ability to inhibit corrosion, although I don't know how. I've heard of coolants described as "organic acid technology", which seems weird to me, like you'd want any kind of acid in your cooling system. ? To me it's more intuitive that you can have the coolant be somewhat electrically conductive if it is a base, or higher than 7 on the pH scale, because bases don't dissolve metal like acids. I just googled it and the general consensus seems to be that coolants are always basic, despite being made up of different chemicals or additives. I supposed I could measure it myself with my old hanna 98129 ec/tds/pH meter, but I doubt the pH probe is still good, after sitting for so long.

the acid technology keeps the aluminum from having a mineral corrosion buildup, the coolant also has parts that constantly refresh the surface between coolant and aluminum if any damage occurs, it prevents the galvanic forces of aluminum + cast iron which means the coolant does not behave as an electrolyte for that purpose, it lubricates seal in water pump, and keeps the corrosion of all metals down

 

[BuickGirlFromMars]

something i found out that I did not know before:

However, there is a downside to all these aluminum components, and some nitrited coolants are notcompatible with the metal. Nitrite can react with Aluminum to form Ammonia, which increases the pH which causes corrosion and degradation to elastomers. In response to these issues, many OEMs call fornitrite-free coolants to be used with machines containing aluminum component

 

[NewLeSabreOwner]

something i found out that I did not know before:

However, there is a downside to all these aluminum components, and some nitrited coolants are notcompatible with the metal. Nitrite can react with Aluminum to form Ammonia, which increases the pH which causes corrosion and degradation to elastomers. In response to these issues, many OEMs call fornitrite-free coolants to be used with machines containing aluminum component

Interesting. Ty

 

[NewLeSabreOwner]

Question for everyone. I did do the many flushes until clear, filled back up, burped the system and she is doing OK. Thank you for all the input. But I have noticed one thing change and thought I would see what you all have to say about it.

If I would look at coolant temp on the dashboard she would usually be around 205* while driving and then if sitting would get all the way up to like 220ish before the second fan would kick on. After doing the flush, now when driving even in this 98* heat, she is at around 192* and then if I sit again without the A/C on she only reaches like 208*. Should I be worried about this change at all? Think I should change the thermostat or my flushes could have hurt it at all. She still warms up like usual but am seeing now these lower driving temps and idle temps, esp in this heat just has me concerned.

 

[2000ltd]

I think your radiator is now flowing more efficiently and the coolant now is flowing with the correct balance of water to coolant ratio so is acting better. Just my opinion. I'd be happy with that result really.