[10068]

I am in WA state, today it was 23F when starting my car. How does a flip of the ignition switch cause parts that are below the freezing point, to go from a standstill to 1000-2000rpm in mere seconds? Think about it, that means that the pistons and other applicable parts are moving up/down roughly 25 times per second. Per SECOND. This using metal that until a couple seconds before was motionless and sub-freezing temperatures.

Furthermore how do the sparks properly ignite and fire at such temperatures? In a state like ours, cold temps are usually associated with increased humidity, so shouldn't this affect performance of the engine as well? Also, how do we design oil to maintain liquidity at such low temperatures? Why doesn't the gas freeze?

And don't even talk to me about new engines which probably incorporate technology to aid against every one of the above - mine is from 1988 and is the basis of these questions.

Science questions are fun

Answers are better!

 

[Joelby]

As far as gas goes - it is only stored as a liquid. It flashes to vapour at a much lower temp then we're going to see in winter. Therefore, it readily burns at even the coldest of ambient temperatures.

Ambient temps aren't a big deal when it comes to ignition. As long as you have the proper fuel/air mix and your spark plugs are in decent shape you're good to go. Cold air is better for combustion as it is denser and contains more oxygen per atmospheric volume then hot air.

Of course, cold starts aren't a good thing for your engine. Those moving parts need proper lubrication and having your oil sit at low temperatures is never good. Here at work, we prelube all our recip machines and even run the lube oil pumps constantly while the machines sit idle during winter. As for your car, the best thing to do is use a block heater when the temps get down below -15C and don't let the car idle for too long when you start it.

Edit: Keep in mind that batteries don't like the cold weather and will lose there charge rather quickly. That's one of the first problems to occur when it gets really cold. Also, you might want to make sure you have the proper coolant/water mixture. It really sucks when your coolant lines burst.

 

[HipHopScribe]

Keep in mind that 0 °C (32 °F) is just the point below which water freezes, other substances react different.

 

[autosound]

Just wondering, why is it bad to idle the car for long when you start it. In the winter, I usually autostart for 5-10 minutes to get the car to operating temps before I hit the road. Any reason why I shouldn't do this anymore?

 

[DanielCox]

It's a waste of fuel. Driving the car (slowly) will warm the engine quicker.

 

[MD1032]

A long as you don't race it when it's cold, your engine should be fine. Modern gas engines can pretty much handle anything, but you'll wear out your engine real fast if you're one of those idiots that things revving it up to 5,000 rpm when it's cold is a good idea. The only problem with cold engines is that the oil isn't circulating yet, thus, turning all those little parts on top of your engine real fast will yield a bunch of really hot little metal parts with no oil on them...bad.

 

[wuwhere]

Relatively, 23F is not that cold. I got stranded overnight once in Indiana in the middle of a winter blizzard where the wind chill dropped to -40F. My Jeep sat on an open parking lot overnight. The following morning it took a few cranks to get it started. At that extreme temp, your oil can jell. So you need to winterize your car with proper oil and flash your radiator with fresh anti-freeze. You can use synthetic oil too, they are pricey but made for extreme temps.

 

[10068]

I've been needing to do a radiator flush anyway... good excuse to finally do it

 

[mrarroyo]

If you all had air-cooled VW's no problem with stinking radiators!

 

[krmathis]

Proper viscosity oil, antifreeze and a well maintained battery is what you need.
I have never had any problems firing up my cars in the wintertime, even if they have spent the whole night out in minus 20°c. A couple of turns and up it fires, regardless if petrol of diesel driven engine.

How "they" do it I do not know for sure, but it works...

 

[Arainach]

Quote:

Furthermore how do the sparks properly ignite and fire at such temperatures?

Spark Plugs are electrical; the spark they generate doesn't care about temperature or humidity.

 

[Todd R]

I spent 2 winters in North Dakota, about 40 mi from Canada.
All the parking lots there have electrical outlets. It's so cold up there that you must have a block heater (a small electrical element that keeps engine coolant warm) installed and plug your car in overnight or it won't start.

We're talking about 25 below ambient temp with a 60 deg wind chill.

23 deg is nothing... it was that cold here today.

 

[Nebby]

Quote:

Originally Posted by Todd R /img/forum/go_quote.gif I spent 2 winters in North Dakota, about 40 mi from Canada. All the parking lots there have electrical outlets. It's so cold up there that you must have a block heater (a small electrical element that keeps engine coolant warm) installed and plug your car in overnight or it won't start. We're talking about 25 below ambient temp with a 60 deg wind chill. 23 deg is nothing... it was that cold here today.

I was going to bring up block heaters myself. That's some cooold weather you got

 

[Uncle Erik]

I've had more trouble starting cars in extreme heat.

Having spent a bit of time in Yuma, Arizona (where it often tops 120), gas evaporates quickly out of a carb. It's easy to flood an engine if you're not careful. EFI has been a lot better, though. I've been able to start my '07 tC without any trouble there, or even when I was up in central Oregon last year when it fell to the mid-20s.

This also reminds me of my recent search for a motorcycle. Many older ones still have a manual choke. It's been awhile since I've used one. I had a 1959 Ford F-100 for awhile that needed to have its choke fiddled when it was cold out. Most newer carbureated cars have automatic chokes.

 

[frozenice]

Ether, that's the ticket. But not too much otherwise you'll blow the cylinder head clean off the block or the oil pan off the bottom of the engine (hint: read the instructions on the can).

Actually, one weak link in the system will cause problems starting. Water in the fuel system can freeze, block the fuel lines and prevent the engine from starting (most fuels in Canada have a winter grade which has alcohol compounds to attach to the water and then they can burn in the engine (fuel and water have a different specific gravity and will separate and also condensation in the gas tank and lines contributes to this problem).

At 40* below the battery is operating at only 25% efficiency because the chemical reaction inside the battery is much slower at those temperatures.

A battery blanket or a battery trickle charger is probably the third best thing to install after the block heater and using synthetic oil, it's a blanket that wraps around the battery and you plug it in and it will generate a little heat to bring the battery temperature up (think electric blanket) and the trickle charger does a similar function by pushing current into the battery and warming the battery up by chemical reaction.