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2.5L coolant and conditioner question

32K views 55 replies 17 participants last post by  GBMaryland 
#1 ·
2.5L coolant and conditioner question (mixed wrong coolant)

(Update on page 4 if you are finding this thread some time after it has been posted)

2011 2.5L with about 89k on it. No issues, drives great, no warning lights, heat blows hot at idle, etc. No symptoms of a coolant issue.

We have another vehicle that I'm currently working through some coolant problems on, which prompted me to take a closer look at the Outback because I can't remember the last time I looked at the coolant. It's been a while, a year or two probably. I know, not smart, but it is what it is.

Coolant was barely visible in the reservoir. Started cold engine, coolant not visible in radiator. I topped up the radiator and then the reservoir to the "full" line with the only coolant I have on hand, a premix that states "safe for all engines American/Asian/Euro."

So, a few questions:

- Do I need the Subaru coolant?
- Do I need the conditioner?

The vehicle could probably benefit from a change and fill as I have not been paying it the attention it deserves, but I'd really like if it could wait until warmer temps here. So, is an off the shelf premix at proper levels okay to get me a few months down the line, or should I be making plans to drain and fill sooner?

Thanks for your help.
 
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#2 ·
I hope you topped it up with "Asian Blue" type of antifreeze (http://www.subaruoutback.org/forums/66-problems-maintenance/221801-subaru-super-blue-antifreeze.html) adding the green stuff will reduce the effectiveness of the metal-protection.

The "Asian Blue" stuff is KNOWN to evaporate and need topping-off every 6 months or so. (add DISTILLED WATER to replace evaporated water)

To answer your question regarding antifreeze replacment... As long as you do not intermix anything but "Asian Blue", the protection lasts a very long time. ( 11years/137,500 miles )
 
#3 ·
BruceP has given you the right advice.

If you added generic green coolant, you may want to start planning on a flush and fill, as you have significantly decreased the life of the coolant. However, if you used Asian blue coolant, preferably Subaru Long Life Super Coolant or water, you are still on target for coolant change at the 137,500 mile service. Based upon my personal research, if it were my car the first choice would be Subaru OEM coolant. And the only other coolants I would put in my car would be Zerex (aka Valvoline) Asian Vehicle Formula or Pentosin Pentofrost A3. The Zerex comes in red or blue, the only difference being color. They are made to match the color of OEM coolants. It won't matter at all if you use red instead of blue.

To your question about conditioner, you only need to add conditioner at flush and fill, not when topping off.
 
#4 ·
It's green colored, I'll get it out of there as soon as I can but I figured proper level is better than not having a clue how much was left.

Is drain and fill as easy as draining from the bottom of the radiator and then filling with the right stuff, or do I need a more involved procedure since it has the green stuff in there now?

The Outback is my first import car. I like a lot of things about it, but they sure are picky with what to use. ;)

Thanks for your help guys.
 
#6 ·
Isn't it already a 50/50 mix?

Evaporation:

Like most modern coolants, Super Coolant is a MIXTURE of Ethylene Glycol, Diethylene Glycol, acid salts and water. Mixtures can evaporate by component, effectively changing the concentration of what's left behind.
 
#7 ·
That’s my point/question (add 50/50 instead of just distilled water from evaporation).
And since the coolant solute is completely compatible/required with water, when the coolant is <212F under pressure, when the pump continuously incorporates the solution – how does the water component evaporate (?).
I agree you can add distilled occasionally, but not regularly. My caution would be if you refill with just water, you need to test the temps protection.
 
#8 ·
It's been a long time since college chemistry. Hopefully I've got this right!

It is complicated. As you know a mixture has unique properties different from the constituent parts. Together, water and glycol boil at a higher temperature than either alone, as they interact and change total molecular motion and thus phase change vs temperature. It's probably also true that the vapor pressure of the mixture is higher than the vapor pressure of the components alone, so the mixed solution might evaporate faster than the component parts. But also remember that a mixture is different from a compound. No matter how 'mixed' the components are, they are still separable by distillation.

In a compound, elements are bound together. For instance, ethylene glycol is a form of double alcohol, made up of carbon, hydrogen & oxygen. It doesn't naturally decompose and loose those components. The hydrogen doesn't go flying off. But in a battery it does, because of the electrical induced decomposition process of hydrolysis. But a mix of ethylene glycol and water should be able to evaporate separately even while they interact with each other. Factional distillation of liquids (boiling) is the most extreme, and best method to rapidly get near pure separation.

Everything generates a vapor pressure across the temperature range. Even at room temperature, the vapor pressure of water is like 20 torr, which is why it evaporates. Now the question is in what order the components of coolant evaporate and if what's left is substantially different from what you started with. I'm pretty sure diethylene glycol has a lower vapor pressure than (mono) ethylene, and both are lower than water so I would think these three can leave at different rates. And then you have the salts, that probably concentrate as the liquids leave?

In a closed, presssurized system, nothing leaves. But we have a bidirectional overflow tank! We pump hot coolant out, and if the tank is vented, something is going to exit.
 
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#9 ·
Hmmmm. I just caught a co-worker on the way to lunch who just happens to be a retired chemistry professor and asked him his thoughts. He agrees that total partial pressure might be higher than the sum of the parts (in part because it leaves the radiator at above normal water boiling temperature), but *thinks* hydrogen interaction might not allow one component to leave substantially earlier than another. But he's going to research it a bit further when time allows.

Sidebar: there is a school of thought that distilled water can be corrosive and that fine filtered (like reverse osmosis) water might be better.
 
#11 ·
Sidebar: there is a school of thought that distilled water can be corrosive and that fine filtered (like reverse osmosis) water might be better.
Are you sure that distilled water is corrosive? I would think it more likely that RO (reverse osmosis) treated water would be corrosive.

Several years ago I managed a test lab that included capabilities for seat belt durability testing, which included salt fog corrosion and an environmental chamber. The water for the salt fog chamber went through quite a polishing process. It first went through sediment and charcoal filters, then softener, next DI, and lastly RO.

Since the environmental chamber generated humidity using an electric water heater element in a 2 gallon brass tank, tap water resulted in a buildup of mineral deposits that were left behind. I had this brilliant idea (sarcasm here) of using the treated water so there would be no minerals left behind. It worked. And it didn't. There were no minerals left behind, but the heater elements kept eroding, and tripping the heater circuit. After the second or third heater element burned out in only a few months, I sought the help of an expert in the field.

What I learned is that my water was too pure. Very pure water is quite corrosive. He recommended I tap into the water after the deionization tanks, but before the RO system. That took care of it. I never had to replace another heater element.
 
#12 ·
Draining and refilling the radiator doesn't get the coolant out of the engine. All the coolant doesn't drain to one spot like oil does, there's additional cavities and holdings in the engine and heater core.

You'll have to flush, pull lower hoses and blow it all out, remove engine drain plugs...if you're going to believe the same sentiments that "mixing is risky" that are causing you to do this in the first place.

Here's what I recommend - plan on a complete cooling system maintenance:
New thermostat, coolant, top and bottom radiator hoses (or at least the lower hose - they degrade quicker due to road/chemical exposure), and the oil cooler gasket and coolant hose.

Here's why - coolant replacement is 137,000 miles, it's not like you're very likely to own this car by the second coolant change, 280,000 miles. In which case there's no difference in doing a coolant maintenance now verses at 137k - either way you're doing one coolant change in the life of the vehicle. Furthermore - if you drive it another 137,000 - you're at 230,000 at which point it's more palatable to not do certain maintenances with such OCD to factory spec's. Power steering fluid, brake fluid, differential oil routinely last the life of the vehicle and never need replaced (I'm not recommending it, i'm just saying it's done all the time - giving plenty of examples that some fluids are far more important than others).


On another line of thinking: How much did you add to the *radiator*?
If it's not much I'd just empty the overflow and wait for warmer weather.
But everyone else is going to say change it and there's certainly nothing wrong with that.
 
#15 ·
Thanks for your help. I'm betting I put about a quart in total, half in the rad and half in the reservoir. I am going to drive it until the weather cooperates and do a flush and some new components then. I am sure I'm not the first person to pour general use coolant that says its safe for all vehicles into one of these engines.
 
#17 ·
What is different in the Subaru rad/engine that the green coolant is not acceptable?

Is this is a documented issue, or just a "well Subaru recommends...."?

If it is a well known issue, why are there so many "green coolants" with labels that state "Guaranteed safe in all vehicles?" Seems like a lot of liability for that coolant producer if their material will cause harm to certain vehicles.
 
#18 ·
I will hazard a guess that "safe in all vehicles" is not the same "as safe to mix with all other coolants." If you thoroughly flush out all of the original coolant, you might be Ok to replace it with an "all vehicles" coolant (although DO NOT take my word on it). But you really don't want to mix coolants with different chemistries. Or you can just play it safe and stick with what Subaru recommends.
 
#23 ·
Good catch! I'll have to check the glove box manual at lunchtime to verify on my '14 (FB Engine). Your '13 FB engine still recommends it. Interesting!

I have most of the manuals in .pdf form, and so far haven't found any mention of Conditioner. MSA5M1404A in Specifications, P12-8 covers coolant capacity & type, Mant & Service / Cooling System, P11-15 covers interval, mixing, total system operation (fans, indicators, fuses), leaks, checking, and that Changing should be left to the dealer! ZERO mention of Conditioner.

I DO NOT have a copy of the US Warranty & Maintenance Booklet soft copy. I have several international downloads, but the Subaru Site doesn't have it. The Aussie and other downloads have no mention of Conditioner either.
 
#24 ·
Continuing to search, and you are (of course!) correct: Both the 2010 and 2014 Subaru Service Manual, page CO(H4SO)-2 has it.
Cooling system protecting agent - Cooling system conditioner - SOA345001
 

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#25 ·
And because confusion abounds on this topic, I thought I'd include this:

Genuine Subaru SOA868V9260 Super Coolant Concentrate (small bottle, you have to cut with water)

Genuine Subaru SOA868V9270 Super Coolant Premix (1 gal jug)
 
#26 ·
Genuine Subaru SOA868V9260 Super Coolant Concentrate (small bottle, you have to cut with water)
this product is for lowering the coolant operating temp to -62F (-52C). :13: label says to draw regular coolant mix out of the rad, and replace it with this at full strength.


as per the label pics and descriptions here,...front label calls it "extreme cold weather" :
https://www.amazon.com/Genuine-Subaru-SOA868V9260-Super-Coolant/


_____

I don't think subaru sells a 50% concentrate to mix with distilled water anymore.
 
#27 · (Edited)
The big difference between the two is the water content.

SUBARU Long Life Super Coolant 50/50 SOA868V9270 is 48-53% water

SUBARU Long Life Super Coolant Concentrate is 3-5% water

$25 a gal (50/50 mix with the water)

$35 for two quart bottles (concentrate without the water)

Take your pick....

If you do a flush, remember that you will not be able to remove 100% of the plain water you introduce. If you only refill with the 50/50 premix, you will end up with substantially less percentage of coolant than what you were aiming for. So to get it to where you really want it (at least a true 50/50 mix), you NEED some zero water concentrate.

And that old Prestone Antifreeze tester you've had in the garage for 30 years probably won't be accurate, because it was calibrated for the specific gravity of pure ethylene glycol / water mix. I suppose you could 're-calibrate' it by trying a sample of today's 50/50 from the bottle, and mark the scale yourself.
 
#29 ·
Okay guys, based on your advice I've decided to do a flush and fill, and replace the thermostat while I'm at it. Here is my shopping list, just wondering if you guys recommend anything else while I am wrenching on the cooling system:

- 6-7 gallons distilled water
- Chemical flush additive
-Subaru premix coolant
- Subaru coolant conditioner
- Subaru thermostat
- Thermostat gasket

My plan is to drain, fill with flush and water, run, let cool. Drain, fill with plain water, run, let cool. Drain, replace thermostat, fill with conditioner and coolant.

How much distilled water should I expect to be trapped after my final drain? How do you guys recommend I get the proper final mix of coolant and water?
 
#30 ·
I don't think anyone is going to be able to give you a definitive answer on this. When I did this on my old Outback, I got out a lot less (5-6 quarts) than what the owners manual suggested was the fill capacity (something like 7-8 quarts?), so there is a certain amount trapped in there. Recovered minus what the manual lists as capacity is what's left behind, and that can leave you underprotected if you only have 50/50 premix.

To aid the process, I will jack up the rear end. I don't think there is a heater core coolant flow valve anymore as there was on older cars, but just to be sure turn the key to 'on' and run the heater. If you try the compressed air trick on a hose, keep the pressure very low!

If you are going to use a hydrometer to test the coolant, start with a sample of the Subaru 50/50 to establish a baseline. The problem is that today's mixes are closer to the specific gravity of water than the Prestone we grew up with, so it's harder to differentiate between a 50/50 vs 40/60 outcome than it used to be.

Oh, and go easy on the chemical flush additive! IIRC, Subaru doesn't recommend these, and given how delicate head gaskets can be you don't want any chemical attack there.
 
#32 ·
Assuming the published number of total system capacity in your owners manual is correct, that procedure should get you pretty close.
 
#33 ·
In case anyone is curious, or someone finds this thread later:

Went to the local dealer to buy premix, full strength coolant, and conditioner. Was informed that the concentrate and premix are two different chemical makeups and are not compatible. They do not use the concentrate on any vehicle that calls for the "Super blue."

Subaru also stopped making coolant conditioner. They couldn't tell me that it was no longer recommended, but if I can't even buy it, and they don't use it, well...

Spoke to the lead tech who said my situation is fairly common and that a drain, flush, drain, fill is more than adequate to "fix" the issue. I did that tonight and went for a quick test drive after, everything seems to be good. If an issue comes up I'll post back here, but if not it means the cooling system hasn't had any problems.
 
#34 ·
Was informed that the concentrate and premix are two different chemical makeups and are not compatible. They do not use the concentrate on any vehicle that calls for the "Super blue."

I don't even know what to say to that.... See the images below from an SOA brochure and the MSDS.

The Conditioner is an interesting issue. It's available as SOA635071 or SOA345001. I was told the same thing a few years ago (no longer for sale, not recommended) by one dealership, and then bought it at another (where the parts guy said they still use it as recommended by the shop manual). If you google it, you'll find both opinions coming up.
 

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