Warming it up

[ladyjaine]

I plug my truck in at night but I'm never sure how long I should wait before driving off afer I start it up in the morning. All I know it that I'm not waiting quite long enough.



What should I be seeing on the gauges? Should I wait for oil pressure to hit a desired range? Water temp isn't going to budge for a while, should I wait that long?



In case I have to drive off before waiting, how should I be driving? Shifting at what rpm to keep it revving high or low or kinda in the middle?



Jean

 

[Dean Upson]

This may not be the right way, but if I am plugged in or if it is fairly warm I just let the truck idle for a couple of minutes and off I go. The sooner you get up to speed, the sooner that heat starts to warm up the cab. I don't think you can idle it long enough to heat up the cab in cold weather. If you are plugged in, the oil is fairly warm when you start up. My "wait to start" light doesn't even come on when plugged in.

I find that the six speed shifts pretty smoothly anywhere from 1800-2500 rpms depending on how much of a hurry I am in. I would say that right in the middle would be pretty good. The transmission seems to shift smoother as you put more miles on it. I always start off in first and leave the pedal alone until the clutch is engaged. Works for me, I have done that with my trailer on and the low speed governor works like a charm.



Dean

 

[EricBu12]

A good way to get the coolant heated up fast is to if you didn't plug in, plug it in and then start it up. the coolant will circulate past the heater and within 3 min, the coolant is up to 70 deg. keep the heater control all the way to hot as well to get that water warmed up.

Within one min after unplug and drive away, you will have luke-warm air.



I keep the revs low to med not over 2000 or so untill 2-3 miles then it is warm enough to do whatever.

 

[EricBu12]

I also make the winter front covers for the 03 trucks.

Look in the classifieds under member basement enterprises

price and all info there

 

[K_Arts]

I haven't had to plug my truck in yet... the temps haven't gone below 20*.



But in the morning I usually start my truck, let it sit for about a minute or 2 and then hit the highway. I have always seen people say not to get the engine above 2000 rpms when cold though I do it every morning without a problem. Of course I am very gentle on the throttle and never exceed 2300. I can say that I keep a very close eye on the oil pressure though. When my truck is cold the oil pressure gets pretty high.



Honestly, once you have voltage and oil pressure, for the most part you can just drive off. Just be a gentle on the throttle and keep your boost low until the engine warms up.



Kev

 

[DNelson]

Jake brake...

Plus, if you have a Jacobs e-brake, you can engage it while idling to warm it up quicker.

 

[Jeremiah]

Originally posted by ladyjaine

I plug my truck in at night but I'm never sure how long I should wait before driving off afer I start it up in the morning. All I know it that I'm not waiting quite long enough.



What should I be seeing on the gauges? Should I wait for oil pressure to hit a desired range? Water temp isn't going to budge for a while, should I wait that long?



In case I have to drive off before waiting, how should I be driving? Shifting at what rpm to keep it revving high or low or kinda in the middle?



Jean

Jean, I just attended a TDR rally at ATS Diesel in Denver. The vice president of Rocky Mountain Cummins said as long as you have oil pressure (upper gauge on the right side) it's OK to drive off as you normally would. He said he WOULDN'T go pedal-to-the-metal right away if he was towing heavy, otherwise, he wouldn't worry about it.



Regarding shift points, I am assuming you are driving a 6-speed. Get it rolling in first, then drop into second just as the rpms reach bottom. The accelerate again in a similar manner through third, fourth, fifth and sixth. Hint: listen to the big rigs drive away from a stop light.



Similarly, down-shift as you slow down. It's easy to down-shift by double clutching. Advise if you don't know how to double clutch.



Otherwise, keep the engine revved up and don't lug it by accelerating in too high a gear. It'll come naturally before you know it.

 

[tgbol]

Jean

I have never had to plug mine in, it just doesn't get that cold here. When I start mine I let it idle for about a minute or so. Then I start down the street slowly for the first 1/2 mile. (It is level. ) The I start up a hill still not laying into it. After a mile or so then I will start legging it a little. I like to circulate the oil in the trans, transfer case, and axles before I put any load on them. Another thought too- when I go to the mountian cabin after a 13 mile pull I will go past it up the canyon a mile or so and then come back down. Letting everything cool down some before shutting down.

 

[Prairie Dog]

Jeremiah, I'm afraid I'm gonna have to disagree with you here buddy. Since brakes are a lot cheaper than transmission's and clutches, I don't downshift when coming to a stop. A lot of owner-operators don't either. As far as shifting, it's best for the trans to let the RPM's drop just slightly and then shift. The reason the big rigs don't usually do this is because it takes so long to shift gears with their design of transmission's (have to double clutch), that their engine speeds drops before they can get it into the next gear.

 

[EricBu12]

DOuble cluctch? Whats that?



I drive truck for a living (watkins-sets of doubles and triples) and I have from just out of school, doing speed shift. Not using clutch for shifting. I have learned to listen to the engine and can do it very smooth and fast. I have been driving 12 yrs now and I drive my Dodge with the clutch mostly but sometimes, I get lazy and do the speed shift. Since I just got the EGR brakes with the Carbon Kevlar Pads, ($150/set) I think I will do downshifts.

 

[DNelson]

Originally posted by EricBu12

DOuble cluctch? Whats that?

I wouldn't speed shift the transmission on your Dodge - the reason we can do without the clutch on a big truck is because of the ""square cut" gear design of a big truck's transmission. Ours don't have that - you're going to wear out the synchronizers and damage the dogs if you do that - or so I've been told. (BTW, I've spent about the same amount of time in big trucks, and I miss clutch-less shifting, especially with the jake-brake engaged! )

 

[Jeremiah]

Originally posted by DNelson

I wouldn't speed shift the transmission on your Dodge - the reason we can do without the clutch on a big truck is because of the ""square cut" gear design of a big truck's transmission. Ours don't have that - you're going to wear out the synchronizers and damage the dogs if you do that - or so I've been told. (BTW, I've spent about the same amount of time in big trucks, and I miss clutch-less shifting, especially with the jake-brake engaged! )

Speed shift? No sir, what I'm talking about isn't a speed shift. If anything, it's the opposite. It's being aware of the where the rear end speed and transmission gearing are and shifting your gears accordingly.



If you want, you can use the clutch and higher rpms to speed up or slow down shift points, but if you're a real professional you'll be able to shift from gear to gear and never feel a jerk one way or the other.



This may not be stated as precisely as an engineer might state it, but I know what I'm doing when I shift through the gears on a diesel engine. And it ain't wearing out no dogs.

 

[Jeremiah]

Originally posted by Dean Upson

This may not be the right way, but if I am plugged in or if it is fairly warm I just let the truck idle for a couple of minutes and off I go. The sooner you get up to speed, the sooner that heat starts to warm up the cab. I don't think you can idle it long enough to heat up the cab in cold weather. If you are plugged in, the oil is fairly warm when you start up. My "wait to start" light doesn't even come on when plugged in.

I find that the six speed shifts pretty smoothly anywhere from 1800-2500 rpms depending on how much of a hurry I am in. I would say that right in the middle would be pretty good. The transmission seems to shift smoother as you put more miles on it. I always start off in first and leave the pedal alone until the clutch is engaged. Works for me, I have done that with my trailer on and the low speed governor works like a charm.



Dean

You're right on target, cuz, according to the Cummins guy!

 

[Jeremiah]

Originally posted by Jeremiah

Speed shift? No sir, what I'm talking about isn't a speed shift. If anything, it's the opposite. It's being aware of the where the rear end speed and transmission gearing are and shifting your gears accordingly.



If you want, you can use the clutch and higher rpms to speed up or slow down shift points, but if you're a real professional you'll be able to shift from gear to gear and never feel a jerk one way or the other.



This may not be stated as precisely as an engineer might state it, but I know what I'm doing when I shift through the gears on a diesel engine. And it ain't wearing out no dogs.

Let me try to explain one more time because I have been driving trucks (and standard shift cars for that matter) for more than 40 years.



"Single-clutching," if that's what you want to call it, means you press the clutch one time as you shift from one gear to another.



Double-clutching means you press the clutch a second time and also the accelerator in order to get the rear end in sync with the transmission, and that becomes the point at which you shift from one gear to another.



Folks, if you don't understand this, get a professional truck driver to demonstrate it for you!

 

[ladyjaine]

Not how, but when!

The question wasn't how to shift, but when. Should I keep the RPMs in the low range when the engine is cold, or run it a bit faster than I usually do? I'm getting the drift that I should not tromp on it and run the RPMs up when the engine is cold. I'll shift it a bit short, and keep the RPMs just a tad to the lower side. No big deal.



Double clutching was never the question. I've been driving manual transmissions since 1981. I long ago figured out double clutching, power shifting, clutchless shifting and side stepping. Not to mention just plain slipping the clutch... I didn't learn from a truck driver, I just listened to my own engine. Baby had been grumping about going in the cold and I wanted to be sure that what I thought was right wasn't going to cause long term damage.



Jean

 

[Casey Balvert]

Jean, I think you will find a couple of thousand miles will make a huge difference in the quality of the shifting. Mine sure improved over that time and it is ccccold here. I shift at 1800 or so until it warms up and then around 2300warm. Unless I want to play Bill Elliot with my 4 ton hot rod. No scientific explanation. Just voodoo.



Casey

 

[Jeremiah]

Re: Not how, but when!

Originally posted by ladyjaine

The question wasn't how to shift, but when. Should I keep the RPMs in the low range when the engine is cold, or run it a bit faster than I usually do? I'm getting the drift that I should not tromp on it and run the RPMs up when the engine is cold. I'll shift it a bit short, and keep the RPMs just a tad to the lower side. No big deal.



Double clutching was never the question. I've been driving manual transmissions since 1981. I long ago figured out double clutching, power shifting, clutchless shifting and side stepping. Not to mention just plain slipping the clutch... I didn't learn from a truck driver, I just listened to my own engine. Baby had been grumping about going in the cold and I wanted to be sure that what I thought was right wasn't going to cause long term damage.



Jean

It doesn't sound like you're doing anything wrong. You already know that diesels are low rpm engines and don't wind up like gasoline engines, and that they're meant to pull powerfully and not be used as drag machines. If the engine is really cold, make your shift points at 22100 or 2200 RPM. Each shift will drop the RPMs back right about where you want them to be (i. e. , you'll stay in the power band). My 3500 SWR runs just fine that way.

 

[Jeremiah]

Originally posted by ladyjaine

I plug my truck in at night but I'm never sure how long I should wait before driving off afer I start it up in the morning. All I know it that I'm not waiting quite long enough.



What should I be seeing on the gauges? Should I wait for oil pressure to hit a desired range? Water temp isn't going to budge for a while, should I wait that long?



In case I have to drive off before waiting, how should I be driving? Shifting at what rpm to keep it revving high or low or kinda in the middle?



Jean

In fact, you can use 1600-1800 RPMs as your cold engine shift point and it won't hurt a bit. But re my msg about shifting at 2100-2200, that's also in keeping with what the Cummins guy said at the TDR rally at ATS Diesel in Denver a couple of weekends ago: "If you have oil pressure, drive the engine normally unless you're pulling something heavy, in which case you might want to let the fluids come up to temperature first. "

 

[K_Arts]

Re: Re: Warming it up

Originally posted by Jeremiah

In fact, you can use 1600-1800 RPMs as your cold engine shift point and it won't hurt a bit.

Jean, If you shift in the Low 2000's you'll be fine. I would refrain from shifting in the 1600 to 1800 range, as this will put your Rpms in the 1300 or so range which will lug your engine!!! Usually below 1500 rpms for our engine will lug them down which is not a good thing.



It sounds like you are doing everything correct. There is no written rule on when to shift, Just listen to your engine and you will be fine.



Kev

 

[Jeremiah]

Re: Re: Re: Warming it up

Originally posted by K_Arts

Jean, If you shift in the Low 2000's you'll be fine. I would refrain from shifting in the 1600 to 1800 range, as this will put your Rpms in the 1300 or so range which will lug your engine!!! Usually below 1500 rpms for our engine will lug them down which is not a good thing.



It sounds like you are doing everything correct. There is no written rule on when to shift, Just listen to your engine and you will be fine.



Kev

Hi, Kev,



I notice that you're driving two auto trannies, neither of which are the HO 2003 common rail version w/the 6-speed. However, you are correct that listening to the engine is the way to go. That's why I first suggested to Jean that shifting in the 2100-2200 range was the best option.



But on second thought, listening to the engine on a 2003 also tells me there are occasions at first start-up when it's possible to use 1600-1800 as a shift point without lugging the engine.



What's also important is that Jean not sit around idling her engine. She should drive off as soon as she has oil pressure and let the engine warm up on the road.