Cold weather, antifreeze.

[JohnG]

I live in the northeast (MA) and we are in the midst of a cold spell (may hit -15 F tonight).

I use a 50-50 mix of conventional (green) antifreeze. Figured this would take care of things and honestly was more concerned with cooling in the summer.

I was disappointed to find that a hydrometer test of my cooling system showed I was only good down to somewhere between +5 and -10 degrees. (the last ball was kind of half floating). This was disappointing.

The usual argument is "well, you never got all the flush out the last time you flushed it". Maybe.

I put distilled water and new coolant carefully into a calibrated beaker. Same reading.

So I called a knowledgeable auto parts store and asked the owner. He said according to the info he gets from companies, the optimal mix is 2:1 (antifreeze to water). The 1:1 might be a general rule of thumb that might work for people in North Carolina and might work for MA but that fine tuning is needed per locale (he is in mid NH so sensitive to such things for his customers).

So your car may or may not be up to the task of a really cold night.

Aside from upgrading the coolant mix, what do you do?

Answer: get some heat under it for the night! Worst case you have to survive 5-6 hours.

Last night I ran an experiment. I put 3 drop lights under the car. 100W each. Put a bunch of blankets on the hood and around the base. Hardly sealed up but taking advantage of the fact heat rises.

While the outdoor temp got down to +1 and the temp in my unheated and drafty garage got down to +12, the temp under the hood was a cozy +23.

A couple bucks worth of electricity is cheap insurance against a cracked block.

Tonight here is forecast for -15 F so I am improving on all aspects during the day. Drain some antifreeze mix, add some pure, bundle it up better. Doubtless I am being overcautious , but the motor is rebuilt, the original block for the body, and has 10K miles. So worth the trouble.

[simplyconnected]

1,500 watts is a whole lot of heat, John. I don't think many engine block heaters are that high. If you think about it, a 1,200 watt hair blower puts out less heat.

Glycol is funny stuff. In pure form it's flamable, and a terrible antifreeze. When you add water, all the good properties come to life.

Here is a chart for Prestone Extended Life Antifreeze:



According to this, you shouldn't need heaters. I would stick to 50/50 or 40/60. I don't think Massachusetts ever gets down to -50*F. Heavy antifreeze is harder for your water pump to push.

So, what did they use in the old days before Prestone and Zerex? Straight alcohol (but it has a low boiling point). I imagine light oil would work too, but glycol is king. Even DOT-3 is based on glycol.

[JohnG]

Dave, all I have is 3 100W light bulbs = 300 Watts.

According the hydrometer today, I am ok to between -10 and -34. That last ball sinks but does not go to the bottom. So taking the conservative route, I am sticking with the lights and blankets tonight.

Yes, I am aware pure antifreeze becomes somewhat slush-like and is a poor idea. Next time I mix any, I will go the 60-40 mix your information suggests and I should be fine.

For the time being, just being cautious.

john

[simplyconnected]

Whew! Dunno what I was thinkin', John. Certainly, an ounce of prevention... and we all have high stakes against the devastating power of ice. It's always smart to err on the side of caution. 300-watts into 1-kilowatt/hr (@~$.25/kwh) costs about 8 cents per hour. That's pretty cheap insurance.

I wonder why your hydrometer gives different readings. Maybe there's more to this story than just specific gravity. Another puzzle is the difference in freeze point from the antifreeze label vs hydrometer readings. I would trust the label.

If you didn't get all the coolant flushed out last time, that means there must be at least some coolant left before you added more. That increases your concentration if you added 50/50.

-4 should be about your low for the coming week, John.

[JohnG]

When I flushed the system, it was first with a commercial product added to water to remove rust etc. Then several times with water until I was convinced I had all the flush out (not knowing if it was harmful to the system if left), so if I did not get it all, I left water in there, to my possible determinent.

My current forecast (zip 01452) is for -14 F tomorrow morning between 6 and 7 am. Without the wind, irrelevant to cars.

At this point I think I'm fine. Never hurts to double check.

[Guest]

I'm glad I don't have to deal with the cold problems you guys have -3C (27F) is as cold as I get here, but then we do get the other end of the scale highest it's been here was 47C (117F) not a day to drive in a non A/C car though, Luckily I have the cooling under control

Richard

[Anders]

I only drive my car in the summer but still use up to 50% glycol as it also works like "anti rust" for the inside of the engine.

[Dakota Boy]

20% antifreeze and the rest is water. Plus a bottle of Water Wetter. Keeps the 460 cool.

I have the luxury of keeping my 'bird in the garage at about 45-50 F all winter long.

The ol' reliable '96 GMC Sonoma (daily driver) has been relegated to sitting outside now. I'm shooting for 20 years outa this truck, but the winter salt is really taking its toll in the last year.

[JohnG]

So we got down to only -8 where -18 was forecast.

The temp in the unheated garage was +10 this morning but the temp under the hood a balmy +23 F ! So the work lights and blankets were worth 13 degrees. Not bad for 3 light bulbs.

[kuusamon]

Ok,like to put in my 2 cents worth about it.

We live in Finland where it is not uncommon to have temp. of -40F(=-40C). We put no tap water with the antifreeze.
The coolant we use is premixed, so glycol(antifreeze) mixed with a kind of purified water. It says on the bottle the min. temp. it is suited for.
Already on a young age I was told by experienced repair shops not to use tap water, only in emergencies, because of the in-purification of it.
The antifreeze ready mix is not only to keep the engine from freezing but also from overheating and rusting.
The boiling point of water is 212F(=100C=373K) and that of glycol( ethylene glycol (EGW) or propylene glycol (PGW)) probably EGW is best.
.....................Pure Water ..C2H6O2/Water ..C2H6O2/Water
................................................50/50 ................70/30
Freezing Point .. 0 C / 32 F ......-37 C / -35 F .......-55 C / -67 F
Boiling Point ..100 C / 212 F ....106 C / 223 F ......113 C / 235 F


Your engine can handle High heat, actually quite a bit higher than the 212F. But what happens when you engine 'overheats' is that the coolant starts boiling and filled up with water much sooner than coolant. Result is that because of the boiling you create air bubbles which pushes out probably half of the liquid and traps air-bubbles in you engine coolant lines and passages. Because of lack of liquid where the airbubbles are and not enough coolant anymore you get unequal cooling, the waterpump dos not move air and the places where there is collant still cools more than places with out. Your engine can not handle it. Heads start to warp and in the worst case the block might crack. So it is not so much a problem that engine is too hot(if the engine is equally hot) but the in equal heating of cooling.

Also tap water and its minerals etc. creates rust and rust comes loose once and a while and clogs up the fine lines in the radiator.
So it would be wise for the life of the engine to use ready mixed coolant, a bit more expensive than mixing it yourself with tapwater but it pays itself back multiple times over in the long run and (even in the short run).
regards
ron

[Guest]

I just mix mine with distilled water ...

been doing it for 40 some years. NO problems. The premixed stuff is fine but you certainly pay a premium for it. Mike

[simplyconnected]

So we got down to only -8 where -18 was forecast...

I just got off the phone with a friend living in North Dakota, near the Canadian Border. She said that since early this morning the snow has been nearly waist high and is still falling. The temperature is dropping way below zero, and the north wind is increasing to near gale force! Her husband has done nothing but look through the kitchen window and just stare. She said that if it gets much worse, she may have to let him in.

[JohnG]

Premix: a remarkable case of paying more for less!!!

Husband out doors: perhaps I should send him one of my work lights and a tarp? Must be a car guy!

[vernz]

I certainly need anti-freeze this year. It was -30F yesterday in Glens Falls, NY, which is 10 miles north of me. We were a balmy -20F. I should have checked the temperature in my garage. On Sunday I participated in an outdoor shooting match and it made it all the way up to +9F. I must like the cold because I won the match.

I've always used 50-50 Ethylene Glycol antifreeze in this kind of weather and have never had a problem. I've used the light bulb trick before and it is amazing how much heat an incandescent light bulb gives off. One concern I'd have is that mice might find the combination of heat and blankets an irresistible combination. I think mice traps might be a good addition to your plan for keeping the engine warm.

Just so you warm weather folks can see the fun you are missing - my wife caught me clearing the driveway.

Vern