Water to Coolant Ratio: How badly did I mess up?

[El_Viajero]

This morning, I was adding coolant to my car. First, I poured a measured amount of water into the reservoir. Then I measured out the same amount of coolant (not the 50/50 stuff, but the straight coolant) and began to pour it into the reservoir as well. The goal was to achieve a 50/50 mix.

But here's what happened: I overestimated the size of the reservoir and was only able to pour in about 25 to 30% of the coolant before I reached the brim. Oops.

Lesson: Mix the water and coolant before pouring.

Anyway, my radiator now contains a ratio of about 3:1 water to coolant. There's a little coolant in there, but it's mostly water. Should I be worried? If it makes a difference, I live in the South and temps won't dip below freezing for 6 to 7 more months.

[zolotiyeruki]

Were you filling the reservoir, or the radiator?  Those are two different things!

There's a lot of leeway in your antifreeze/water mix.  There's also a fair amount of coolant capacity in the pump and all the water lines as well, so don't worry about it.  Go run your car until it warms up (i.e. thermostat opens), then check the coolant levels.  Chances are there'll be room for more antifreeze.

[nereo]

This is not a problem

As zolotiyeruki mentioned, if you're adding the diluted mixture to a system that already has some coolant in it, your resulting ratio will be higher than what you put it (assuming it was 50/50 to begin with).

Even if it's not, a 1:3 ratio will give you a good deal of antifreeze capability  in your climate.  If the final mixture is 25% ethylene glycol and 75% water, you will have a freezing point of 10ºF.  If you're worried, in the fall either drain your coolant and put a higher concentration in or siphon some out and put straight antifreeze in to increase the ratio.

The 50/50 ratio is already overkill for anyone who lives in an area that's never seen temperatures below -10ºF.

see this table for ratios: http://www.erareplicas.com/427man/engine/antifreeze.htm

[lthenderson]

They make devices that tell you for what temperature your coolant is rated too depending on the amount of glycol in the system. I don't know if an autoparts store will loan those out to customers or not but I would check. If not, they are made out of plastic and not too expensive. I found some online for $15. You simply stick it into your reservoir and suck up a bit of solution and it will show you the temperature your coolant is good for. Being in the south, I wouldn't be too worried.

[sokoloff]

Other posters are spot-on in terms of it being a non-issue for the South. The more water you have, the better it will cool anyway. You want some antifreeze for lubrication and anti-corrosion purposes, but you're in good shape there with what you have.

The only thing I'd add that hasn't been covered is that under normal operation, your car doesn't "use" any coolant, so if you have to continually add coolant, you have a problem that you should look into. Could be a head gasket (coolant escaping into the oil or combustion chamber), a leak in a hose, seal, or water pump. In any case, have a look.

[Chranstronaut]

Other posters are spot-on in terms of it being a non-issue for the South. The more water you have, the better it will cool anyway. You want some antifreeze for lubrication and anti-corrosion purposes, but you're in good shape there with what you have.

The only thing I'd add that hasn't been covered is that under normal operation, your car doesn't "use" any coolant, so if you have to continually add coolant, you have a problem that you should look into. Could be a head gasket (coolant escaping into the oil or combustion chamber), a leak in a hose, seal, or water pump. In any case, have a look.

A quick check for anyone with head gasket leak concerns is to check your oil.  If it's milky or cloudy, it means that your coolant has been leaking into your engine.  New engine oil should be translucent brown, used oil may be opaque and darker brown.  If it's foamy and/or milky on your dipstick, oil cap or when you drain the oil pan, you've got a leak.

[El_Viajero]

Were you filling the reservoir, or the radiator?  Those are two different things!

Good point! I was filling the reservoir. I hope that's what I was supposed to do?

This is not a problem [...]

The 50/50 ratio is already overkill for anyone who lives in an area that's never seen temperatures below -10ºF.

Ok, good deal. It never gets that cold where I live. Thanks, everyone!

[Spork]

Were you filling the reservoir, or the radiator?  Those are two different things!

Good point! I was filling the reservoir. I hope that's what I was supposed to do?

There's nothing wrong with filling the reservoir.  (And by filling, there is usually a line that says "full hot" and one that says "full cold".  Filling doesn't necessarily mean to the top.)

But... it's different to add a quart to the reservoir vs flushing/filling the entire system.  The reservoir is an overflow/underflow.  It sucks from it when there is a vacuum on the system and it bleeds extra to it when there is over pressure.  It is a small slice of the entire cooling system.

[guitar_stitch]

The more water you have, the better it will cool anyway.

That is not completely true.

Water does have better thermal capacity than antifreeze, but that's only in liquid form.  Inside the engine, straight water can flash to steam in the water jackets, which significantly reduces its capacity to remove heat.  You'll also create hot spots, which leads to uneven expansion of the head/block under pressure - potential for cracking and warping.  Antifreeze in proper proportions will help keep the water from flashing off to steam.

The cooling capacity of the medium is irrelevant if the thermostat is working properly anyway.

I hope moreover that OP used distilled water and not tap/liquid rock.

[Gibbelstein]

I would not worry about it.  Even at 3:1, the ratio of coolant in the reservoir vs. the volume of the rest of the system will should dilute pretty quickly.  If you are hyper paranoid (or just curious) you can check it with this http://www.amazon.com/Prestone-AF-1420-Antifreeze-Coolant-Tester/dp/B000BOA9RY kind of tester.  You just suck some coolant from the radiator into the tester and see where the needle points.  Again, you should have nothing to worry about. It was just in case you are curious.  I think guitar_stitch's point above about using distilled water is a slightly bigger deal when it comes to coolant maintenance. 

[Syonyk]

:/ I just buy the 50/50 mix.  Fire and forget.  I might be able to save a little bit if I go hunt distilled water, but I don't generally keep that on hand, so I'd have to go specifically pick it up somewhere.

In any case, if you're messing about with the plastic reservoir tank, you really can't mess things up much.  It'll get cycled into the rest of the system and evened out.

But if you are going through a decent amount of coolant, it's a good idea to figure out where it's going.

[PeachFuzzInVA]

You're fine. When I used to race, we ran a 70/30 water to coolant ratio because it does keep the engine cooler due to water dissipating heat better than coolant. In the future, just buy the 50/50 mix. Save yourself the time and hassle of having to keep an extra jug around to mix on your own.

[Spork]

The 50/50 mix always pissed me off.  If it were half the price, I'd buy it.  But it's not.  You're paying about 50% more for water and more packaging.  It's the pound of bacon that now weighs 12oz.  For the amount of upcharge: I'll just mix mine.

[Syonyk]

The 50/50 mix always pissed me off.  If it were half the price, I'd buy it.  But it's not.  You're paying about 50% more for water and more packaging.  It's the pound of bacon that now weighs 12oz.  For the amount of upcharge: I'll just mix mine.

Do you carry distilled water around as well, or do you premix and carry that with you?

I get that it's more expensive, but it's correct, not using tap water (or hose water), and is nicely sealed up in one container, not two.  Which is perfect for carrying around in the car.

... or do you own a vehicle that doesn't require carrying coolant around? :p  I've owned so many cars that leak that it's just habit now...

[Spork]

The 50/50 mix always pissed me off.  If it were half the price, I'd buy it.  But it's not.  You're paying about 50% more for water and more packaging.  It's the pound of bacon that now weighs 12oz.  For the amount of upcharge: I'll just mix mine.

Do you carry distilled water around as well, or do you premix and carry that with you?

I get that it's more expensive, but it's correct, not using tap water (or hose water), and is nicely sealed up in one container, not two.  Which is perfect for carrying around in the car.

... or do you own a vehicle that doesn't require carrying coolant around? :p  I've owned so many cars that leak that it's just habit now...

None of my vehicles require me to carry it around.  I always have distilled water around for other various uses... and if I'm doing a flush/fill, I just buy more.

I've done all sorts of stuff over the years in emergencies: Pissed in the radiator, filled it from a drainage ditch, etc.  Not the best plan, but it gets you home.  Flush/fill, start over.

[Syonyk]

Fair enough. Vehicles that don't leak or burn coolant at some rate are new to me. :)

[Spork]

Fair enough. Vehicles that don't leak or burn coolant at some rate are new to me. :)

I've had a pretty fair number that leak other fluids.  I've mostly had all or nothing with cooling systems.  Either they hold or they fail dramatically and spill it all.

[Drifterrider]

As someone else mentioned, get an antifreeze tester.  $6-$7.  any auto parts store.

[guitar_stitch]

I've done all sorts of stuff over the years in emergencies: Pissed in the radiator

I shall remember this next time I have plans to taste test a mystery fluid to see if it's coolant or rainwater/condensate.