Better to idle or better to drive on a cold engine

[ISX]

There was a post about this and I wanted to really dive into it and see everyones opinions and stuff on the issue. So it is 0F out and you go out to your truck and fire it up. From the way most sound at 0F, you will surely wait 30 seconds before doing anything else. But after that, then what is best to do? Here is my theory. When you start the engine, the first thing to get warm is the piston. It is aluminum and in direct contact with the explosion above it. The next thing would be the exhaust valve though it's composition would resist it. Then I think the rest would be relatively uniform. The thing I see here is that the piston would be hot and therefore expand. The cylinder walls would have 0F coolant rushing past them and being steel they would not be heating up much at all. Therefore, I think this accelerates wear on the rings until the cylinder walls reach operating temperature. While idling, the engine is really not making much heat. I can idle mine for 10 minutes and be lucky to hit 80F from 0F. If I waited for 100F before I left, it would be idling a longgg time. Over the course of this duration, how much wear am I causing?On the other hand, what if I started driving after that 30 seconds, not hard, just putter out of the driveway and slowly get up to 55mph (I live on a highway). This would make it heat up faster, but would the shorter duration make up for the cylinder strokes? After all, it would be turning 1600RPM or something instead of idle speed.. Seems doing this would be more likely to polish the cylinder walls, ridding them of the crosshatch. My EGT's are also very high on a cold engine at 55mph, scratching 600F. A warm engine is barely over 400F. So it is producing more heat but is it worth the wear of whatever it is wearing that is making the engine so hard to turn which makes me give it more fuel and the EGT's show the load. I'll get some interesting calculations up in a bit. I believe driving is better on it, but I am not sure, that's why I am posting this...

[Mopar1973Man]

Subscribing...

[ISX]

Forgot I was going to add info.

[dripley]

I dont start my engine in 0* weather very often and colder does make some differance. But I figure when you start it up that he oil should be circulating every in 30 to 60 seconds. Not as good as in a warm engine, but until it gets warm it is just the way it is. I can idle mine on a cold day(15* to 20*) for along time for it to warm up enough to kick off the e brake(it kicks out at 140*). So i start up, idle for 30 to 60 seconds, put it in gear and idle to the highway, maybe 2 minutes. Then i just baby it until I see the temp come up or the oil pressure come down. Short of plugging in the block heater, what else can you do? Surely these engines are built to withstand some cold starting and driveing whithout prematurely killing them in the cold.Oh! I was going to add some info, but I DONT HAVE ANYY!!:lmao2:I dont mean nothing by that, ISX. Please dont take it personal, it was not meant that way.

[ISX]

I dont start my engine in 0* weather very often and colder does make some differance. But I figure when you start it up that he oil should be circulating every in 30 to 60 seconds. Not as good as in a warm engine, but until it gets warm it is just the way it is. I can idle mine on a cold day(15* to 20*) for along time for it to warm up enough to kick off the e brake(it kicks out at 140*). So i start up, idle for 30 to 60 seconds, put it in gear and idle to the highway, maybe 2 minutes. Then i just baby it until I see the temp come up or the oil pressure come down. Short of plugging in the block heater, what else can you do? Surely these engines are built to withstand some cold starting and driveing whithout prematurely killing them in the cold. Oh! I was going to add some info, but I DONT HAVE ANYY!! I dont mean nothing by that, ISX. Please dont take it personal, it was not meant that way.

Not sure what I was supposed to take personal lol. These things are tough, all diesels are, so you are really just meaning the difference between going a million miles and 900k miles lol. But I would like to know what has more effect on them. I idled mine every day before I went to school and the thing ran perfect, started perfect, it would start without the grid heaters at 0F instantly with a tiny puff of smoke just the same as a 100F day. Come college I started it while it was cold, never warming it up, 3 or 4 times a day. During that time it got worse and worse and now will now takes 10 seconds of cranking to start at 15F as attested to by last monday, this was without grid heaters (still havent hooked them up). I guess I said driving off was better in the first post but now I see I am contradicting myself. It is possible that other things could have done it. Hard to say. I might have to start googling and see if I come up with any actual lab tests of this stuff.

[anoldbiker]

I really don't worry of the 0* temps, but it always seemed to me this is why you use something like 5w-40 or 0w-40 oil for these kind of days. If you let the oil circulate for 60 sec or more in that extreme cold, then drive slow, your lubrication would minimize or sort of nulls the wear factor. ???

[cumminapart]

My opinion is that loading the engine with exhaust brakes and 3 cyl high idle is no diff than lightly driving to warm the engine upHowever I also like to be comfortably warm when I get in to drive In my mind higher egts would mean that the cylinder walls get more of their heat energy for warming up from the burning gasses rather than friction and friction is wearAs u said the difference is going to be minimal As long as we dont get in and floor it everything should be goodI warm it up for a bit for comfort but I don't worry too much if I have to get going

[dripley]

Not sure what I was supposed to take personal lol. These things are tough, all diesels are, so you are really just meaning the difference between going a million miles and 900k miles lol. But I would like to know what has more effect on them. I idled mine every day before I went to school and the thing ran perfect, started perfect, it would start without the grid heaters at 0F instantly with a tiny puff of smoke just the same as a 100F day. Come college I started it while it was cold, never warming it up, 3 or 4 times a day. During that time it got worse and worse and now will now takes 10 seconds of cranking to start at 15F as attested to by last monday, this was without grid heaters (still havent hooked them up). I guess I said driving off was better in the first post but now I see I am contradicting myself. It is possible that other things could have done it. Hard to say. I might have to start googling and see if I come up with any actual lab tests of this stuff.

Just joking with ya on the additional info.got alot of respect for a man that will try and skip a motorcycle over water.

[Mopar1973Man]

My opinion is that loading the engine with exhaust brakes and 3 cyl high idle is no diff than lightly driving to warm the engine up However I also like to be comfortably warm when I get in to drive In my mind higher egts would mean that the cylinder walls get more of their heat energy for warming up from the burning gasses rather than friction and friction is wear As u said the difference is going to be minimal As long as we dont get in and floor it everything should be good I warm it up for a bit for comfort but I don't worry too much if I have to get going

There has to be some difference between driving and high idle with a exhaust brake. Because the fact driving you phyiscally demanding the engine to push the truck along but with high idle you creating a virtual load by partial plugging the exhaust and creating pumping resistance. The effect is the overlap of the valve blows some of the exhaust back in the manifold warming the manifold slighly also with the exhaust brake you trapping the heat in the engine without blowing it out freely. Just my 2 cent right or wrong...

[Wild and Free]

Just for reference Volkswagon doesn't want their TDI's to idle at all, start them and drive them easy for a couple miles and then normally. They emphasize and repeat this all over the owners manual.Personally if its around freezing I just wait for a minute or so and then go easy for a couple miles if below freezing I let cylinder temps get built up a bit usually let it at minimum run until grids quit cycling then go easy for a couple miles. If the temps are above 50 I let the oil pressure come up and go, if I am pulling a trailer I will go easy first couple again.Having been around pretty much every application a diesel can be in and working on them I have seen no adverse effects or any shorter engine life by starting them and just putting them to work in cold weather without much warm up.

[cumminapart]

Yea Mopar I suppose you're right the exhaust brake would trap a little bit more heat energy to warm things up.. Didn't really think about that

[Mopar1973Man]

[dripley]

My e brake alone brings my egt's up to 400*. when I idle out of the rv park it stays on until I hit the highway. Gives it a decent headstart on warm up.

[cumminapart]

What I mean by not much difference is that some people make a big fuss about giving extensive warm up time but what's the difference between loading the engine to make higher egts while idling or loading it by lightly driving until it warms up I just didn't think about how some energy is being kept within the engine using an exhaust brake compared to driving you loose a lot out the tailpipe --- I am here: http://maps.google.com/maps?ll=42.773605,-84.595496

[dripley]

Log before I had an ebrake I used to crank it up and let it run for a while. I gave up on that method after seeing little temp rise by idleing. After that I just started driving it to warm it up after idleing for a few minutes.

[98whitelightnin]

I used to be an idler as that is what my dad always did. We always had gas trucks/cars but he would idle 3-5 minutes no matter the outside temp to let it warm up good. He bought a new honda in 94 and put 365k on it only replacing batteries and 1 starter, some of those miles were mine and my brothers. Then he sold it to my cousin and she traded it for a new kia:doh:. Dad is the kind to turn everything off before he turns the car off like a/c and radio. I was raised that way so I always turn the a/c off too byt not the radio. He is a very peculiar man as I always tell him. Now I just let oil pressure build and take off like old man river and drive like its Sunday until 170 or so. Funny, after dads mid-life crisis he crankes and goes too.

[ISX]

Googled this on lunch break, I'll read more of it at home and search more. www.dadacanada.com/idling-facts-and-myths/idling-myths.html I guess we have 3 things now, idling/idling with ebrake/driving. I was trying to find solid evidence that one way was the best but need to Google more when I get home. I know everyone has their own preferences but I want solid proof. I shall not fail! That link does make a good argument about how idling does nothing for all the other components. I used to idle my Ford in neutral so the auto tranny would be getting somewhat warmer.

[Mopar1973Man]

ISX you going to have to come up with something a bit un-biased than that link...

[ISX]

Oh. I didn't see what the site was about from the tiny perspective of my cell phone

[Mopar1973Man]

Oh. I didn't see what the site was about from the tiny perspective of my cell phone

I personally think idling has a lot to do with environment that it does with anything else. Look at northern part of Canada and Alaska most vehicles are left running 24 hours a day to hold temp up other than that extreme cold takes it toll on getting started again. Now on the flip side of the coin you guys down there in south that have very mild weather shouldn't have to worry about warm up much at all. Like right now here in Idaho its been so mild I've not bother idling much just fire up and get rolling. Once again don't get me wrong by the time I get the truck out of the garage and close the door it had plenty of time to pump oil around.