Low Coolant level @ 20k? Help..

[Jfheisenberg]

Originally Posted by _gt86_user

I'm not really losing coolant it's just dissipating in the reservoir, boxer engines like to go through coolant it's just a normal thing, don't expect to go to the dealer and tell them to fix the problem that isn't there. When I say a tiny bit I'm talking millimeters in my reservoir after the car has been driven hard or fully warmed up from a long drive, if you don't see higher temps or drive very conservatively and are losing coolant then yes something is wrong. Just trying to save you the headache is all, all I'm really saying is you should be checking your fluids more often than you think, this car isn't a corolla or civic or anything and I promise you will find posts like this in all Subaru forums .

Interesting thanks, now that i think back, i remeber that my subaru svx used to consume a lot of coolant as well, like you said, might be a boxer thing. ill buy some coolant from subaru sometime this week. so based on the pictures should i fill it up all the way to full? Even after car is warm the coolant fluid is still low.

[_gt86_user]

Originally Posted by Jfheisenberg

Interesting thanks, now that i think back, i remeber that my subaru svx used to consume a lot of coolant as well, like you said, might be a boxer thing. ill buy some coolant from subaru sometime this week. so based on the pictures should i fill it up all the way to full? Even after car is warm the coolant fluid is still low.

If the car is fully cold like sat over night than fill to about the halfway mark on the resivior right in between low and full, just drive it around for about 20min or so give or take however long it takes for the fans to cycle on at least a few times then go back turn off the car and you should be able to immediately open the hood while it's warm and see if the resivior level is at full if it is than you my friend are done! Just make sure you were fully warmed up if you have an OBD2 reader to track temps that helps, you just want your coolant to be around 189 or so, than you know it was warmed up.

[humfrz]

Originally Posted by Jfheisenberg

Interesting thanks, now that i think back, i remeber that my subaru svx used to consume a lot of coolant as well, like you said, might be a boxer thing. ill buy some coolant from subaru sometime this week. so based on the pictures should i fill it up all the way to full? Even after car is warm the coolant fluid is still low.

@Jfheisenberg ........ I'm ah feared you are overthinking your situation.

Points to ponder:

Assuming no leaks in the cooling system, most of the loss of the coolant mixture is due to evaporation/dissipation of the water part of the mixture. A simple check of the vapor pressure of ethylene glycol compared to the VP of water will show that.

The blue coolant stuff is roughly 50% water.

Therefore, most of the mixture that is disappearing (not leaking) , is water.

The system holds about 7.5 ish quarts.

I might take a pint of liquid to top it off.

So, if the system is a little low, why not top it off with distilled water.

The manual says to fill the reservoir up to the full mark when the engine is cold.



Now, relax ........


humfrz

[mav1178]

Originally Posted by Jfheisenberg

Thanks but i feel like if you need to add coolant every two weeks, then something most be really wrong.

Here's what's wrong:

The coolant reservoir tank sits directly above the headers.

Put a 200F source of heat next to a cup of water, and see how long that water lasts...

Don't overthink this. It evaporates, sometimes faster if you sit in traffic or otherwise heatsoak the engine bay.

As for what to put in there, any distilled water is fine. You can even mix in Subaru coolant or fill entirely with Subaru 50/50 coolant if that makes you sleep easier at night.

-alex

[Jfheisenberg]

Originally Posted by mav1178

Here's what's wrong:

The coolant reservoir tank sits directly above the headers.

Put a 200F source of heat next to a cup of water, and see how long that water lasts...

Don't overthink this. It evaporates, sometimes faster if you sit in traffic or otherwise heatsoak the engine bay.

As for what to put in there, any distilled water is fine. You can even mix in Subaru coolant or fill entirely with Subaru 50/50 coolant if that makes you sleep easier at night.

-alex

I want to sleep better at night, so im buying some blue subaru coolant =D

[Tcoat]

Originally Posted by Jfheisenberg

I want to sleep better at night, so im buying some blue subaru coolant =D

Time for my normal statement on this subject!
That tank is a coolant expansion reservoir and is not directly related to the cooling system of the car. It's only purpose in the system is to deal with excess coolant when it expands in the rest of the system. When hot it will force coolant into the tank and when cool it will suck it back into the system. Back in the day the overflow was blown out a tube onto the road but the tree huggers tend to frown on this now.
Because that tank is low does not mean your system is low. As long as there is a drop left in the bottom that means the system it's self is full. In reality it is possible that the system has never needed to add or take back a drop of what was in that tank and it has simply evaporated without even going into the rad.
As said several times there is no need to put actual coolant on there. The components of the coolant do not evaporate but just the water does. Just fill it with distilled water and it will keep your coolant at the right mix. If you keep pouring coolant in and evaporating the water off then it will eventually thicken up (very eventually but it will).
If it makes you feel better then you can alternate fill ups between pure water and coolant but there is no real need to.

[humfrz]

Originally Posted by Jfheisenberg

I want to sleep better at night, so im buying some blue subaru coolant =D

Well, now, Jfheisenberg ....... you are one stubborn puppy ......

Back in the day, you would have been correct, in adding more "antifreeze".

Why? Because back then, we had to use alcohol added to the water in cooling systems to keep them from freezing.

Why did we add more alcohol instead of water .. ?? Because the alcohol boiled/evaporated off before the water.

Get it ... ??


Your call ......


humfrz

[_gt86_user]

Above statements are correct-a-mundo! Use your best judgement, if you want to have the coolant on hand just buy some, if not add water as you see fit.

[stevesnj]

Originally Posted by humfrz

I'd suggest you just add some distilled water to bring up the level.

I believe for the metallurgy of our engines you need to use deionized (demineralized) water.

[Ultramaroon]

Originally Posted by stevesnj

I believe for the metallurgy of our engines you need to use deionized (demineralized) water.

Distilled water is deionized water.


Guys, it's simple. Leaky radiator cap.


I drive the piss out of mine all the time. I use zero water. Zero.

[humfrz]

Originally Posted by stevesnj

I believe for the metallurgy of our engines you need to use deionized (demineralized) water.

Well, now, @stevesnj, you are partially correct in that deionized or demineralized water can be used in our car's cooling systems.

However, it's my understanding that since distilled water does not contain any inorganic compounds, it too may be used in the cooling system.

Yes, distilled water may contain some organic compounds, if they have a similar boiling point to that of water. However, the deionization process typically does not remove any organics.

Like ol @Ultramaroon was eluding to ....... I don't think the cooling system in the FA20 engine gives a rip whether the water has been distilled or demineralized or deionized ..........



humfrz

[stevesnj]

Originally Posted by Ultramaroon

Distilled water is deionized water.
Guys, it's simple. Leaky radiator cap.

Deionized water is a purer version of distilled water with lower Ph levels and less minerals than distilled water. But i know I saw somewhere where Subaru says to use Deionized water in their blue 50/50 coolant.

And yes a bad cap would allow the water in the coolant to vaporize but there would also bee higher coolant temps because of a pressure reduction.

[humfrz]

Originally Posted by stevesnj

Deionized water is a purer version of distilled water with lower Ph levels and less minerals than distilled water. But i know I saw somewhere where Subaru says to use Deionized water in their blue 50/50 coolant.

And yes a bad cap would allow the water in the coolant to vaporize but there would also bee higher coolant temps because of a pressure reduction.

It's my understanding that distilled water, cannot contain any amount of inorganic minerals. Why? Because the minerals that contaminate water have a higher boiling point that water.

Pick it up @Ultramaroon ......


humfrz

[Ultramaroon]

Originally Posted by stevesnj

And yes a bad cap would allow the water in the coolant to vaporize but there would also bee higher coolant temps because of a pressure reduction.

High pressure maintained by a properly sealed system allows the coolant to reach higher temperature without simmering/boiling in the hot spots. The temperature variation is not a function of pressure.

What does change when the cap has a pinhole leak is the temperature at which the coolant begins to simmer. Those little bubbles travel to the high points in the system, one of which is the leaky radiator cap so "bloop bloop," while you're driving the bubbles invisibly escape right through the coolant reservoir. Then, when the engine cools down, the remaining internal bubbles, which are pure water vapor, condense and the entire space is taken up by liquid from the reservoir.

The boiling rate is a function of the heat input and the flow rate of the leak.