Idle on a cold day

[fdcg27]

Originally Posted By: Lubener
In my area, if you want to idle your car, you better be nearby. The police will issue tickets to anyone who leaves a vehicle running, unattended.


While it is true that it is unlawful under ORC to leave a vehicle idling in the driveway, around here at least any officer who values his job has better things he could and should be doing than acting as the idling car enforcement officer.
ORC or not, most cops have more important things that they're expected to do with their duty time.
For the record, it was around 15F this morning with light snow coating the two vehicles my wife and I drove to work and I idled both of them in the driveway for about fifteen minutes before we both left for work.
Engines don't warm up at idle?
Idle nonsense.

 

[asleepz]

I warm up my cars like I warm up my marine diesels... Oil pressure and go...

Caterpillar 3508 - 47K hours of trouble free service Straight 40 wt
John Deere Marine Generator Set - Fires up straight to 1800 RPM 15 seconds later switch load. 25k hrs x 2 no problems but a head gasket on one. Straight 40 wt
Ford Powerstroke 6.7 73k miles 5w-40
92 Accord 124K miles 5w-30 or 5w-40 depending

 

[jmb3675]

I just met a guy that used to start his Escort every 6 hours if it got colder than -10f. He said it was hard to start or wouldn't start otherwise. Turns out he was using 10w-40 because that is what his dad said to use and that is what his dad used in his Jeep.

I use the remote start and let it run for 10 or 15 min. I like getting in a warm car and hate scraping windows. With the remote start my Focus gets about 22 miles per gallon and i'm ok with that.

 

[jayg]

Originally Posted By: fdcg27

Engines don't warm up at idle?
Idle nonsense.


Depends on where you live. At -40F ,especially a diesel, it will take near forever at just idle to come up to temp.

Originally Posted By: asleepz
I warm up my cars like I warm up my marine diesels... Oil pressure and go...

Caterpillar 3508 - 47K hours of trouble free service Straight 40 wt
John Deere Marine Generator Set - Fires up straight to 1800 RPM 15 seconds later switch load. 25k hrs x 2 no problems but a head gasket on one. Straight 40 wt
Ford Powerstroke 6.7 73k miles 5w-40
92 Accord 124K miles 5w-30 or 5w-40 depending




Of course that works for you. You live in Louisiana and you aren't "warming" up much.



At -40F, I let my Land Cruiser idle enough that my gear oil allows me to put the transmission in gear and that the cabin temp on the inside is warming enough that it doesn't instantly fog and freeze from my body temperature. I have a block heater, oil pan heater, and heated blanket but the rest of the driveline is still -40F and isn't ready to drive off once i "reach oil pressure".

This is usually about 10 minutes on the coldest of days, others it's 5 minutes above -20F and take it easy until its up to temp.

The folks on here that let their vehicle warm up for 20 minutes because it's +30F or more are just silly to me. Turn it on, give it 30 seconds and drive it. Wear gloves, wear a coat. It doesn't have to be 80F cabin temperature before you go anywhere does it? You can do what you want and spend what you what. I'm just saying thats pretty [censored] soft.

 

[veryHeavy]

Why do old carburetor cars need warmup time?

I rev to 3000 and wait for temperature needle to move. Then I drive away. The engine is not fully warm, but I figure it's better than driving on cold oil that is barely pymping.

 

[CELICA_XX]

Should You Warm Up Your Car Before Driving?

by Engineering Explained

https://www.youtube.com/watch?v=xKALgXDwou4

 

[jayg]

Originally Posted By: veryHeavy
Why do old carburetor cars need warmup time?

I rev to 3000 and wait for temperature needle to move. Then I drive away. The engine is not fully warm, but I figure it's better than driving on cold oil that is barely pymping.


Don't rev to 3000 rpm until the temperature needle moves. Cold oil then holding it at 3k rpm right after you turned it on until the needle moves is likely causing more wear than just having it idle for a few minutes.

Why do carbureted vehicles need more warming time? I'm not sure if that's a rhetorical question or not but ill bite.

They don't have feedback sensors reporting to a computer telling it exactly how much or little fuel to inject based on the temperature outside? It's done mechanically that has no way of knowing air intake temp, coolant temp (to an ecu), barometric pressure etc.... so instead the choke (electric or manual) gets you pretty close until it's warm enough that you don't need it. Even at full choke on my truck or 240 when it's well below 0F, it's going to be a handful to drive for a few minutes unless you want to buck and hesitate down the road the first few miles.

 

[69GTX]

Originally Posted By: jayg
.... Nobody learns anything or changes.


I learned something I didn't know before....by running across an interesting video showing key temps/pressures during the 20 minutes of an actual idle warmup. Hadn't seen that in anything posted in 2016 or 2017. Would like to see something like that only in more detail with more accurate gauges. Someone has them on their cars like Steve20 did. I don't care about what people do unless they present facts to back up their methods....I want to know what the engine systems are actually doing via real data. I'd also like to read an engineering study done on wear/corrosion during the time oil temp is heating up from -20F to +170 deg F and the various effects of spending considerable time in each band.

 

[HemiHawk]

Originally Posted By: jayg


At -40F, I let my Land Cruiser idle enough that my gear oil allows me to put the transmission in gear and that the cabin temp on the inside is warming enough that it doesn't instantly fog and freeze from my body temperature. I have a block heater, oil pan heater, and heated blanket but the rest of the driveline is still -40F and isn't ready to drive off once i "reach oil pressure".

This is usually about 10 minutes on the coldest of days, others it's 5 minutes above -20F and take it easy until its up to temp.

The folks on here that let their vehicle warm up for 20 minutes because it's +30F or more are just silly to me. Turn it on, give it 30 seconds and drive it. Wear gloves, wear a coat. It doesn't have to be 80F cabin temperature before you go anywhere does it? You can do what you want and spend what you what. I'm just saying thats pretty [censored] soft.


You do see some cold temps! jeez. I wouldn't let me car idle for 20 minutes around 30F, but I would for around 5 minutes. Not sure if its just my location, or elevation or what, but fog/frosting/condensation is a problem. heated side mirrors and rear defrost take care of most of it, but its simply not even safe to drive if you don't have some heat for the front defrost.

Also, like some others have said, I've recently come around to the fact that the car is there to serve me. If that means a 5 to 10 (max for my area) warm up time, I'm doing it. lately for me though it does come down to safety.

 

[alarmguy]

Originally Posted By: Triple_Se7en
If it's that cold at 5 degrees, I give it a two minute warmup, then drive softly for the first mile at-least.


^^^ that ...

 

[veryHeavy]

Originally Posted By: jayg
Cold oil then holding it at 3k rpm right after you turned it on until the needle moves is likely causing more wear than just having it idle for a few minutes.

Even if I do nothing, the car automatically revs to 2500 rpm when cold. That's how the Honda engineers programmed it.

And if I drive down the highway without warmup (as recommended by various agencies) then the car will be doing 2500-to-3000rpm, but with the added burden of dragging a car down the road.

 

[veryHeavy]

Originally Posted By: jayg
Carburetor cars don't have feedback sensors reporting to a computer telling it exactly how much or little fuel to inject based on the temperature outside? It's done mechanically that has no way of knowing air intake temp, coolant temp (to an ecu), barometric pressure etc.... so instead the choke (electric or manual) gets you pretty close until it's warm enough that you don't need it.

Thank you. I've never owned one, so never had to deal with that.

 

[HemiHawk]

Originally Posted By: veryHeavy
Originally Posted By: jayg
Cold oil then holding it at 3k rpm right after you turned it on until the needle moves is likely causing more wear than just having it idle for a few minutes.

Even if I do nothing, the car automatically revs to 2500 rpm when cold. That's how the Honda engineers programmed it.

And if I drive down the highway without warmup (as recommended by various agencies) then the car will be doing 2500-to-3000rpm, but with the added burden of dragging a car down the road.



My Civic SI with the K20 was like that on startup. At certain temps it would just *whaaaaaaaaaaaaaaaaaaa* at idle. In those cases I waited for the revs to drop, which they did in a couple of minutes. That car really hated the cold. I imagine it was just something built in to heat it up quicker, for emissions. The SI also had a rev limiter when the engine was cold. I dont think it would let you go past 6k RPM when cold (redline around 8200).

 

[tmorris1]

Originally Posted By: aquariuscsm
I always let mine idle until the temp gauge begins to move.

Which is about 30 seconds in Texas.

 

[asleepz]

I've lurked on here for the better part of 10 years or so and I've always wondered if these threads pop up just for that "one guy"

"I fire it up, do a rolling burnout in reverse out of the driveway, sit there and smoke em for about 60 seconds to warm the tires up then go on my way"

 

[supton]

Originally Posted By: veryHeavy
Originally Posted By: jayg
Carburetor cars don't have feedback sensors reporting to a computer telling it exactly how much or little fuel to inject based on the temperature outside? It's done mechanically that has no way of knowing air intake temp, coolant temp (to an ecu), barometric pressure etc.... so instead the choke (electric or manual) gets you pretty close until it's warm enough that you don't need it.

Thank you. I've never owned one, so never had to deal with that.


Also, the fuel goes into the intake manifold (also applies to throttle body injection / aka TBI) with the air. Unlike port (or direct) injection. This makes a difference. Liquid gasoline does not burn, it has to be vaporized. A carb is a fancy fuel leak and as such the fuel goes into a cold space, with cold air rushing over it. The gasoline has a hard time turning into vapors that can be burned. Idling can help heat up the intake manifold; many intakes had an exhaust crossover passage for that purpose.

Port injection squirts just ahead of the intake valve, which is going to be warmer (closer to the cylinder) and offers a straight(er) shot into the the cylinder, with less places for the gasoline to drop out of the air. Also, due to higher pressures, the fuel is "forced" into smaller droplets, unlike a carb. [TBI setups were also hindered if the injectors were above the throttle valve--the fuel had to hit the mostly-closed flap, which of course was being cooled down the incoming air--that couldn't have helped.]

Carb and TBI setups often had a heat riser setup, offering heated air coming off an exhaust manifold. There would be some fancy covers on the exhaust manifold, and a piece of tubing (sorta like dryer hose) going to the intake cleaner housing. Inside that was a bimetallic control which would switch from cold air (the other intake location) to this preheated air (all of this ahead of the air filter). Not sure if I've seen a PFI setup with this, but I'm no mechanic and have worked on very few setups.

 

[2KBMW]

This question always seem to pop up every winter. I read this somewhere in a car mag years ago that
made sense to me. This persons view is on warm up only and does not take into account snow, ice buildup etc.

Temp. above 32F (0C), no warm up, wait till idle drops and drive slowly till warmed up.
Temp. 0F to 32F (-18C to 0C), warm up two min's. and drive off slow.
Temp. below 0F (-18C), warm up for five min's. and drive off slow.

What you are doing is fine.

 

[cmlind]

Start up the truck, scrape the windows, fill the wood furnace and if the windows are clear go. Ran for about 3 minutes this morning at -10°F and I took off and drove easy the 1/4 mile to the highway. Seats were kind of stiff and the power steering doesn't do much at that temp. Just take it easy for the first few miles. Sometimes I need a few more minutes to let the windows clear if they are fogging up inside.

If the windows are clear I give it 30 seconds and go if below 10°. If above that just wait until rpms drop some.

 

[slybunda]

my neighbour gets in her car in the morning and hold it at max rpm for 30 secs then drives off. shes had the car foe 8 years and still going fine!!! ???

 

[69GTX]

Originally Posted By: slybunda
my neighbour gets in her car in the morning and hold it at max rpm for 30 secs then drives off. shes had the car foe 8 years and still going fine!!! ???


Probably still on the factory oil change as well. Some people are just lucky.