Is my car really in danger from the cold?

[Zsofia]

You may have seen in the news that we're having an unusual cold snap here in the South. Now, when up North I've seen ads for "winterizing your car" and just shrugged - I mean, I guess they do something with antifreeze or something? Anyway, I don't know anybody who does anything like that down here to their cars.

My mother's having conniptions about my car - I lied and told her I parked in the heated garage last night because I just didn't want to deal with it and I was too tired to nag my boyfriend into moving his motorcycle and stuff around. Anyway, she's flipping out because my car is even now sitting in a parking lot, gasp, outdoors, and it's below freezing and "your engine block is going to crack!"

Now, it's been cold before, you know? Granted, it isn't usually in the teens, but it's been cold, and my engine block certainly hasn't cracked. Is my car really in any danger, either from sitting in the parking lot in the sun (not likely, IMHO) or me leaving it out of the garage for another cold night? I heard 25 tonight, not nearly as low as last night.

[Casserole]

-3 degrees Celsius?

It's currently -13 degrees C here (8 degrees Fahrenheit), and many people here leave their cars outdoors.

[Johnny L.A.]

The way cold usually cracks an engine block is by freezing the coolant. The coolant expands and exploits any weakness in the block, causing it to crack. Most people use antifreeze in their cooling systems to prevent this. In the event that someone uses straight water or not enough glycol or it just gets that cold, engines have 'freeze plugs'. These are plugs in the engine block designed to pop out if the liquid freezes, giving the ice somewhere to go instead of cracking the block.

[UncleRojelio]

Does it have antifreeze in the cooling system? Is the antifreeze at the correct mixture? If so, you are good to go.

[Johnny L.A.]

Originally Posted by UncleRojelio

Does it have antifreeze in the cooling system?

Antifreeze for Volkswagen (original) Beetles.

[Zsofia]

Originally Posted by UncleRojelio

Does it have antifreeze in the cooling system? Is the antifreeze at the correct mixture? If so, you are good to go.

Uh, how would I know?

[Johnny L.A.]

If you have antifreeze, your coolant will appear 'neon green'. The ratio I've always heard is 50/50 distilled water and antifreeze. (You don't have to use distilled water, but it's cheap enough.)

[Zsofia]

Is that something they do when I have them change the oil at the dealership? (It's humiliating to have to admit that while I have a theoretical understanding of what goes on under a car's hood, I give it to the guys in the jumpsuits and when they give it back to me I drive it away. I put the key in, I drive it places, it goes. Every so often I think to check the oil.) How do you even see what color your coolant is anyway?

[Zsofia]

I asked my boyfriend if we're supposed to be doing stuff with antifreeze and he said "Isn't that for cold places?" So if I'm a moron I'm not alone.

[Johnny L.A.]

Originally Posted by Zsofia

I have a theoretical understanding of what goes on under a car's hood,...

That sounds like me! IANA mechanic.

To look at your coolant, take off the radiator cap. The coolant should be visible. If it isn't, it's low.

They don't change the coolant when you take the car in for an oil change. That's called a coolant change and costs extra. I think this is different from a 'cooling system flush', I stand to be corrected. A change in my mind is simply a drain-and-fill, while a flush gets rid of sludge and other deposits in the system. I've heard people say that a 'flush' is a waste of money. Drain-and-fill? Seems like a good idea from time to time.

[Rick]

Well actually I have seen the color of antifreeze, just a few times mind you, but I have seen it.
What year is your car?
To the best of my knowledge all modern cars use a mixture of coolant and water in their cooling systems. For simplicity's sake we will call it antifreeze (even if you live in the desert it is still called antifreeze)
The antifreeze/water mixture does several things. first off it lowers the freezing point of the mixture below 32F, secondly it raises the boiling point above 212F, and lastly, and in some ways most importantly it inhibits corrosion inside the engine.
Almost any % mixture of antifreeze and water will protect down to 25F that is actually not that cold.
Antifreeze can be a number of colors depending on the type of antifreeze and the dye used when it is made. yellow, green, blue, neon green or yellow, red, or orange are all very common colors.
In any event, your car maker probably specifies a change interval for the antifreeze in your car. Assuming the shop you are taking it to is even 1/2 on the ball, they probably have kept up with this service schedule or even exceeded it.
If you are still concerned about your car, tonight just before you go to bed, go out and run your car for say 10-15 minutes and get the engine good and warm. shut it off and go to bed. All that heat generated by running the engine will take some time to dissipate, and you should be good to go. Now if you lived in Cannuckastan, this advice would not apply, but where you live it should be fine.

[Johnny L.A.]

Originally Posted by Zsofia

I asked my boyfriend if we're supposed to be doing stuff with antifreeze and he said "Isn't that for cold places?" So if I'm a moron I'm not alone.

Antifreeze also raises the boiling point of the coolant and inhibits corrosion.

EDIT: Master Rick beat me to this post.

[Zsofia]

It's a 2004 Pontiac Grand Prix. Really what I ought to do is kick my boyfriend's ass into moving his motorcycle so I can park in MY GARAGE. They say it hit 19 last night in my area (they were forecasting 10) but I think it's only supposed to do 25 tonight, which my car has seen before.

So if a modern car has a coolant mix already in it, it doesn't need "winterizing" or whatever?

[pulykamell]

Originally Posted by Zsofia

It's a 2004 Pontiac Grand Prix. Really what I ought to do is kick my boyfriend's ass into moving his motorcycle so I can park in MY GARAGE. They say it hit 19 last night in my area (they were forecasting 10) but I think it's only supposed to do 25 tonight, which my car has seen before.

So if a modern car has a coolant mix already in it, it doesn't need "winterizing" or whatever?

I don't do anything special to my car for the winter (other than the usual checking of fluid levels), it's a 2004 Mazda 3, and it started up fine at -10F yesterday. You should be fine.

[Rick]

Originally Posted by Zsofia

It's a 2004 Pontiac Grand Prix. Really what I ought to do is kick my boyfriend's ass into moving his motorcycle so I can park in MY GARAGE. They say it hit 19 last night in my area (they were forecasting 10) but I think it's only supposed to do 25 tonight, which my car has seen before.

So if a modern car has a coolant mix already in it, it doesn't need "winterizing" or whatever?

Again if you lived in Cannuckistan, winterizing would consist of making sure the antifreeze mixture was concentrated enough for the expected low temps, making sure that there were winter wiper blades on the car, and the windshield washer solvent was of the antifreeze type (yes they make a special low temp windshield fluid for cold places). They would also test the battery to make sure it has enough power to start on a cold winter morning. Plus probably a few more things that I am unaware of, living in sunny Southern California.

[Chefguy]

Originally Posted by Zsofia

Uh, how would I know?

If your car has an air conditioner, you've already got antifreeze in your coolant. If this is the case, 25 degrees isn't going to be a problem.

[Rick]

Originally Posted by Chefguy

If your car has an air conditioner, you've already got antifreeze in your coolant. If this is the case, 25 degrees isn't going to be a problem.

Why do you say that?
I would agree that if you have AC it probably has antifreeze in the system, there is nothing that prevents AC from working even if there is pure water in the cooling system.

[Harmonious Discord]

Nobody sells cars or changes the coolant without putting antifreeze in them. Antifreeze is also for the boiling point and rust inhibitor properties. Unless you have been adding water to the cooling system your fine. Winterizing also includes being sure you have a 5W-30 or 5W-40 oil in the engine before it gets really cold.

[Johnny L.A.]

Originally Posted by Harmonious Discord

Winterizing also includes being sure you have a 5W-30 or 5W-40 oil in the engine before it gets really cold.

As I found out last month!

[Gary T]

Only an ignorant fool, or someone in some particular type of dire emergency, would fill the engine's cooling system with just water, rather than the standard antifreeze/water mix. Thus it's pretty safe bet that your coolant is what it ought to be and that it won't freeze and crack the engine block. Your mother is apparently projecting some stories from ages ago (based on what were poor practices even then) onto modern automotive reality. It's a virtually certainty that she's woefully misinformed and just wrong.

"Winterizing" is for the most part an outdated concept - a holdover from the days when cooling systems used just water in the warm months and alcohol in the cold months, requiring twice a year changes to avoid cracked blocks (frozen water) or severe overheating (boiled away alcohol). A winter readiness check (antifreeze mixture right? battery okay? wipers good? heater work?) makes sense, but generally there's nothing to do to actually "winterize" the car.

[Carson O'Genic]

Rick already gave the straight dope answer. I'm just chiming in to warn about removing the radiator cap. Being female means you will heed the three foot high warning decals pasted all over the cooling system, but people do funny things when they're worried or frustrated.

[Mr. Slant]

Check this chart:
http://www.ketemalp.com/pdfs/glycol_...oint_table.pdf

It tells you freezing temp by % glycol vs water.
Change out the radiator fluid based on the interval suggested by your automaker.

[Mr. Slant]

Originally Posted by Harmonious Discord

Nobody sells cars or changes the coolant without putting antifreeze in them. Antifreeze is also for the boiling point and rust inhibitor properties. Unless you have been adding water to the cooling system your fine. Winterizing also includes being sure you have a 5W-30 or 5W-40 oil in the engine before it gets really cold.

Also, remember that your oil is in part low-temp capable due to chemical additives installed in the oil.
If your oil is really, really tired or contaminated, it might have turned from 5W30 to 10W30.
Asides:
I saw an anecdote by a tribologist about early-90s-vintage Castrol Syntec + Mobil 1 5W30 products turning into 15W40 when mixed, but I think that kind of problem is not a current going concern.
Also, many, "energy-conserving" thin 5W30 products turn into thick 5W20 products by the time you hit your oil change interval.

[Chefguy]

Originally Posted by Rick

Why do you say that?
I would agree that if you have AC it probably has antifreeze in the system, there is nothing that prevents AC from working even if there is pure water in the cooling system.

I'm just saying that the antifreeze already present for the AC would be enough to protect the engine at 25 degrees. My comment had nothing to do with operating the AC.

[billfish678]

Originally Posted by Johnny L.A.

Antifreeze also raises the boiling point of the coolant and inhibits corrosion.

EDIT: Master Rick beat me to this post.

Inhibits corrosion is another biggy.

Even if you live in the perfect climate where it never gets below freezing or particulary warm you REALLY need "antifreeze" for the anti-corrosion aspect, particularly in modern cars...and it doesnt hurt to get it changed every so often.

I've heard of more than one person RUINING an engine by running a weak antifreeze solution or even straight water !

Oil changes and antifreeze changes are dirt cheap compared to car payments, even minor repair bills, or gawd forbid the early demise by even a few months of a car that would have lasted longer with the slightest bit of tlc.

[Athena]

I've lived in cold places my whole life, and I don't do a damn thing different in the winter than in the summer. It's really nice to have a garage to put your car in for the winter months, but that has everything to do with MY comfort, not the car's - I don't have to brush snow off or be miserable for that first ten minutes before the car heats up if it's in the garage overnight.

[Zsofia]

Originally Posted by Carson O'Genic

Rick already gave the straight dope answer. I'm just chiming in to warn about removing the radiator cap. Being female means you will heed the three foot high warning decals pasted all over the cooling system, but people do funny things when they're worried or frustrated.

Oh, don't worry - it's because I'm a girl that after I called my boyfriend to ask him if he knew anything about the stuff in the radiator that I called him back to say, "Now, you DO remember that you DON'T open that radiator cap when the car's been running, right? Right?"

[Gary T]

Originally Posted by Chefguy

I'm just saying that the antifreeze already present for the AC would be enough to protect the engine at 25 degrees. My comment had nothing to do with operating the AC.

The disconnect here is that antifreeze isn't present for the A/C. Antifreeze is in the engine's cooling system to reduce the chance of the coolant freezing, boiling away, or causing corrosion. It's there whether the car has A/C or not. Essentially, its presence has nothing to do with the A/C.

[NinetyWt]

Zsofia, you can get a little tester which tells you what temperature your antifreeze mixture is good for. You test some of the mixture and the thing shows "-10" for example.

Hubby went around and checked all of our vehicles & tractors with his the other night, just to be sure.

I wouldn't depend upon freeze plugs to save an engine block. I've seen them with all the plugs pushed out and still cracked. YMMV.

[Chefguy]

Originally Posted by Gary T

The disconnect here is that antifreeze isn't present for the A/C. Antifreeze is in the engine's cooling system to reduce the chance of the coolant freezing, boiling away, or causing corrosion. It's there whether the car has A/C or not. Essentially, its presence has nothing to do with the A/C.

So there's no possibility that running the AC may cause the engine to overheat?

[Kevbo]

In addition to inhibiting corrosion, anti-freeze serves as a biocide to prevent alge blooms if the car is not operated for long periods (getting it hot regularly will prevent alge)

[spike404]

"..engines have 'freeze plugs'. These are plugs in the engine block designed to pop out if the liquid freezes..."

Not to be a nitpicker, but the "freeze" plugs are actually core plugs, and are installed to plug the gates where the molten metal was introduced when the engine block was cast. They MAY give some freezing protection, but not to the small channels in the block. BTW--from the factory they are steel, and highly susceptible to corrosion. The replacements are brass/bronze and are more resistant.

Just keep your coolant in the proper concentration, and flush the system every two years or so. There is NO lifetime coolant! Also, never mix different types of coolant. Some are green, and some are orange; they are different.

A short anecdote: Many years ago I had a plug rust out on a '64 Chevy. The leaking plug was behind the motor mount (some are in the back next to the transmission!). I had to jack up the engine, disconnect the motor mounts and remove them. Then wrench out the damaged plug, and drive in a new brass plug. About four hours work, for a fifty-cent plug! I did both sides.

[Rick]

Originally Posted by Chefguy

So there's no possibility that running the AC may cause the engine to overheat?

Engines create heat when they burn fuel. they create a lot of heat. As you increase the load on the engine even more heat is created, and must be dealt with by the cooling system. Turning on the AC system imposes a load on the system. Will that load be enough to cause the car to overheat? That depends on a bunch of factors.
Can running the AC on a car with no antifreeze in the cooling system, cause it to overheat? Maybe, maybe not. It would depend on several factors including the design of the system, and condition of all the various components. Bad pressure cap? Might cause to overheat when with a good cap it might not. Internally plugged radiator, externally dirty radiator, a radiator that is not large enough, a poor design with crappy airflow, and the condition of the fan or fans could also maybe cause an overheating condition if run with just water instead of a mixture of antifreeze and water.
Ambient temp, and how the car is driven are also a huge factors. Going up a steep hill at 80 mph in 84F degree weather can easily cause overheating, while driving on level ground at 50 mph in 104F degree weather the car might be just fine.
I would also point out that the above factors could also cause a car with antifreeze to overheat in some cases. in other cases it would not.

The bottom line here is just because a car has AC there is no guarantee that there is antifreeze in the cooling system.
I have been in the business long enough to recall cars that had AC and didn't have antifreeze in the cooling system. So get off my lawn!

[Rick]

Originally Posted by spike404

"..engines have 'freeze plugs'. These are plugs in the engine block designed to pop out if the liquid freezes..."

Not to be a nitpicker, but the "freeze" plugs are actually core plugs, and are installed to plug the gates where the molten metal was introduced when the engine block was cast. They MAY give some freezing protection, but not to the small channels in the block. BTW--from the factory they are steel, and highly susceptible to corrosion. The replacements are brass/bronze and are more resistant.

Just keep your coolant in the proper concentration, and flush the system every two years or so. There is NO lifetime coolant! Also, never mix different types of coolant. Some are green, and some are orange; they are different.

A short anecdote: Many years ago I had a plug rust out on a '64 Chevy. The leaking plug was behind the motor mount (some are in the back next to the transmission!). I had to jack up the engine, disconnect the motor mounts and remove them. Then wrench out the damaged plug, and drive in a new brass plug. About four hours work, for a fifty-cent plug! I did both sides.

To pick even more nits, there are engines nowadays that don't have freeze / core plugs in the block.

BTW accessible freeze plugs never rust out. It is one of the immutable laws of the universe.

[Gary T]

Originally Posted by Chefguy

So there's no possibility that running the AC may cause the engine to overheat?

Well, it's possible. Running the A/C puts more heat load on the engine. It won't cause overheating if everything's in good order, but if some cooling system components are faulty or marginal, then using the A/C could make the difference between overheating or not.

I'm not sure if we're on the same wavelength here, though. It seems to me you're saying that antifreeze is used in the engine coolant because the car has A/C, to which I'm responding no, antifreeze is used regardless of the car having A/C or not having it. I can't imagine any car sold in the U.S. over the last several decades, with or without A/C, left the factory without antifreeze.

Am I failing to understand something?

[LSLGuy]

And lots of people, particularly in warm climates, add water and only water when the coolant level is low. Good mechanics may do it right, but folks who top their own at the gas station every 9 months whether it needs it or not are gonna use what they have on hand: water.

So when the car was new the correct 50/50 or whatever mixture as installed. Over the next 10 years in the Carolinas, perhaps 5 gallons of water has been added & the coolant is now 97 (or whatever) % water.



Zsofia's question was not "In a world of ideal auto maintenance, would my coolant be good for 20F overnight", but rather, "Given that I have no knowledge of the coolant maintenance history of a 15 year old car kept in a warm climate, is it guaranteed to survive a 20F night?"

The answer to that question is: "Its not guaranteed to either survive or to not." If you're down to pure water, you are runnning a risk of permanent damage from overnight freezing if you don't run the car a few minutes to heat it up prior to bed time. OTOH, if it has been maintained by a dealer or quality shop & you've been paying for coolant fills all along, then it's completely safe, just like it was when it was new.

Only the OP can say where in that spectrum her reality lies.

[Satellite^Guy]

Zsofia, for the record, I don't do anything special to my vehicles in the winter that I don't do in the summer, until the temp gets colder than about -20c (-4f), at which point I plug in the block heater (in the explorer... my Civic doesn't have one, and I rarely use the Civic when it's that cold)

S^G

[flodnak]

Originally Posted by Athena

I've lived in cold places my whole life, and I don't do a damn thing different in the winter than in the summer. It's really nice to have a garage to put your car in for the winter months, but that has everything to do with MY comfort, not the car's - I don't have to brush snow off or be miserable for that first ten minutes before the car heats up if it's in the garage overnight.

Your car will also be happier if parked in a warmish garage on a cold night - not because the engine block might crack, but because an engine running on cold oil will experience an awful lot of wear and tear until that oil warms up.

It's not going to kill the car, but it might shorten its lifespan.

[Bolt the Nut]

A few additional thoughts. Many cooling systems have an overflow reservoir. It is under the hood of your car, and often looks like another windshield washer fluid container. Except, this one will have a thin hose running to it from the radiator. When your car is running (and the engine hot), the coolant expands in volume and the excess will be pushed out into this reservoir. When it gets cooler, the extra is sucked back into the cooling system (kind of like a straw). There are usually high and low marks on the reservoir (the lower one is often marked as “full cold” and the higher one is often marked as “full hot”). This is where you should check your coolant – do not open the radiator cap if your car has been running in the last hour, as there is a chance you could be burned by escaping steam.

The tester mentioned in post #29 works by sucking the coolant mixture into the clear middle portion, and the needle “floats” to a given location based on the specific gravity (i.e. the viscosity or thickness) of your coolant – water mixture. (The black thing on top is a squeeze balloon – kind of like the top of a turkey baster.) Think of coolant as similar to liquid laundry soap in thickness, and when you mix it with water it gets thinner. The thinner the mixture, the lower the anti-freeze protection. Thus, if the mixture is really thin, the needle will sink far to the bottom, letting you know there is little cold protection.

If you don’t have a tester, or don’t want to buy one, then look at the color of the fluid in the reservoir. If it is at least mildly green, you have some antifreeze protection. The darker the green, the greater the protection (most antifreeze is green). It is easier to see the color in the reservoir, as they are frequently made of white plastic. It is virtually impossible to see the color when looking directly into the radiator (remember – it is also dangerous to open the radiator cap on a recently running car). If you don’t have any fluid in the reservoir, try running the car for 10 minutes and then check it again. If you still don’t have any fluid in the reservoir, check your car’s manual, as you may have to add water + coolant.

Also, coolant won’t kill you if you touch it, but it is poisonous if swallowed.

I hope this helps, and that you get warm soon .

[billfish678]

Originally Posted by Bolt the Nut

Also, coolant won’t kill you if you touch it, but it is poisonous if swallowed.

I hope this helps, and that you get warm soon .

And another note.

Coolant is BOTH poisonous AND tastes pretty good too, nice and sweet. Or at least used to, havent tasted any lately.

Do NOT leave it out for even a short time where small children, dogs, cats, birds, or thirsty alchoholics can get to it !


Bolt that was a good post.

And those testers are pretty darn cheap as well and quite handy. One other point about em. When you are testing the water/coolant, make sure the little swinging needle things doesnt have any air bubbles stuck on it when you take the reading. If there are any, you can usually dislodge them by thumping the tester fast and hard with your finger.

Also, if its an older car with an unknown history. It would be a good idea to go ahead and change out the coolant, and maybe a flush as well. Make sure you get the right type of coolant for that particular make/model of car.

[enipla]

A 2004 Pontiac? As others have said, you are almost certainly OK. It often gets to -20 f here. I don’t do anything special for my 2006 Nissan. If I recall, the standard 50/50 coolant mix is good to -34.

Winterizing also means a general check up on the car. Which you should really do all year long. But it is good to make sure things are in ship-shape before the snow falls.

Wiper blades - snow and ice plays hell on them. It’s good to have a nice new pair before it hits.

Rubber. People that live in snow country pay particular attention to the tires they have. It can be a serious debate topic.

Coolant/anti-freeze and coolant level. Again this is just as important to prevent overheating than freezing.

I keep tools/blanket/tow straps/first aid in my car year round. But I suppose some people accessorize in the winter only.

As others have said. Take a peak at the color.

But DO NOT open the radiator cap when the engine is hot. You could and likely would get hurt by hot coolant and steam.

[Uosdwis R. Dewoh]

Cold starting a car can really wear on the engine. According to this article (sorry, couldn't find a English cite), cold starting an engine can be the same as driving 1000km in warm temps. The average Finn wastes 10% of their yearly fuel consumption on cold starts. The common wisdom over here is to pre-warm your car (everyone here has a block heater) in temperatures under 5°C/41°F.

Always have warm clothing with you in the car even if your just driving a short distance. Your car might be warm and comfortable when the engines working, but if it breaks, you're going to get cold really fast.

[Mr. Slant]

I saw some guys work out the advantages of pre-warming vs not pre-warming their vehicles with US gas and electricity prices.
As of last week, the cost savings for plugging your car in were under 1 cent per day.

That being said, these guys were gas-mileage fiends with small cars. You might get up a few pennies if you were driving a Ford F350 or something.

If your Finnish compatriots are actually burning 10% of their fuel due to cold starts, Finns must live VERY close to work and school.

Re: warm clothes
Yes, excellent idea. I also keep a blanket in the trunk.

[billfish678]

Originally Posted by Mr. Slant

I saw some guys work out the advantages of pre-warming vs not pre-warming their vehicles with US gas and electricity prices.
As of last week, the cost savings for plugging your car in were under 1 cent per day.

.

Is that just the FUEL savings or saving from the extra wear and tear on the engine due to REALLY cold starts.

And besides wear and tear, when its really cold, I imagine that is when you could get catostrophic failure due to something getting stuck so to speak from the cold.

[Mr. Slant]

Engine wear wasn't calculated in that.
To be honest, it seems like the internally lubricated elements of modern gas engines are the most reliable part of the car.
With or without cold starts, the actual engine seems to outlast the car 99% of the time.
If I could find a car where the transmissions routinely made it to 250K just like the engines do, I'd put it high on my shopping list.

[elfkin477]

Originally Posted by Zsofia

It's a 2004 Pontiac Grand Prix. Really what I ought to do is kick my boyfriend's ass into moving his motorcycle so I can park in MY GARAGE. They say it hit 19 last night in my area (they were forecasting 10) but I think it's only supposed to do 25 tonight, which my car has seen before.

So if a modern car has a coolant mix already in it, it doesn't need "winterizing" or whatever?

How long have you had the car? Obviously you haven't checked the anti-freeze level. It does go down after time so just because it came with the proper level of fluid doesn't mean it will, particularly after four years if you've never worried about it before. For example: I noticed that my engine's heat meter was almost topped out one night in October, and thought it was a little strange. You don't worry about a car overheating, at night, in October around here. When I check the anti-freeze level the next day, I figured out that it had gone very low, and needed to be refilled. They sell a gage to help you figure out what temps your anti-freeze is good for, and it's usually less than $5. I think you should pick one up.

[Zsofia]

I tried to get one of the little testers, but here's not an antifreeze gauge left in town. It doesn't get cold here very often and they were forecasting the end of the world. I ordered a pizza last night without thinking and it took almost two hours to get here - I asked the guy if they were really busy because of the cold and he told me they made eight thousand dollars the first cold night.