Diesel newbie-operating questions

[etpm]

Recently I bought my first diesel engine. This 40 year old engine came complete with a 40 year old Yanmar YM2310 tractor wrapped around the engine.
The manual says to pull the throttle handle all the way to full throttle, pull the decompression knob out and crank the engine until it starts. Once it starts set throttle to 1500 RPM or lower and let it run for at least 3 minutes before using the tractor. When stopping the engine it should be run at an idle for 1 minute to cool off before shutting down.
I have questions now about how to run this engine. I live just north of Seattle so the temperatures the engine will experience will be pretty moderate most of the time. Is it really necessary to run the engine for 3 minutes to warm it up? if so then why? And do I really need to idle the engine for 1 minute to cool it down? It's not that hot here usually and when we do have weather above 90 degrees I'm not gonna be running the tractor anyway.
I see folks who let their diesel engines idle away for long periods of time on a pretty regular basis. Not just big trucks but pickup trucks, backhoes, excavators, and small engined equipment like my tractor. I shut off my gasoline engined Case 580 CK backhoe rather than let it idle for more than a few minutes. Is it a bad thing to shut off my diesel, shovel stuff into the loader, and then restart it after maybe 5 minutes to do more work? And to do this several times a day?
For the next couple days I will be using a rock rake on an area I will be planting with grass. After a few passes with the rake I sort out and shovel all the rocks into the loader and then dump all the rocks into a hole I dug with my 580CK for this purpose. It takes 5 to 10 minutes to do this shoveling and sorting. I don't like having to let the diesel idle while I sort and shovel. So that's why the above question is asked.
I guess my last question for now is about fuel. I use the diesel fuel that comes from the pump right next to the gasoline pump at my local gas station. It's the same fuel that over the road vehicles use. I know it is low sulfur fuel and that 40 years ago engines were designed to use different fuels. On top of that, my engine was designed to be used in Asian countries, not the USA, and maybe their diesel was significantly different than the fuel available to me today. Because of this I am using a diesel fuel additive that is supposed to clean injectors and increase the cetane rating. Should I continue to do this?
Thanks,
Eric

 

[mrmikey]

These are just my opinions so take it for what they're worth and what you paid :

Is it really necessary to run the engine for 3 minutes to warm it up?

I always let my engines run a bit before I do anything with them, truck, tractor, chainsaw, trimmer or what have you. I have a remote start on my truck and I always start it a bit before I'm ready. My theory is everything will reach their operating temperature and clearances before there's any load on the engine as well as lubrication gets where it's supposed to.

And do I really need to idle the engine for 1 minute to cool it down?

Cool down is kind of a misnomer, equalize temperatures would be a better description IMHO unless you're referring to a turbo. Again, I do the same to any engine powered piece of equipment.
Friend of mine had a turbo something truck. He'd come to work right off a 110KPH highway and shut the engine off....I'd cringe thinking about the oil coking around the bearings in the turbo.

Is it a bad thing to shut off my diesel, shovel stuff into the loader, and then restart it after maybe 5 minutes to do more work? And to do this several times a day?

Depends...if it's been run hard from dumping the load to come back to be filled up, I'd leave it running. If you can just idle back to the location for a couple of minutes I'd shut it off.
If you're working it and then have to do something else, I'd let it idle for a bit.

Because of this I am using a diesel fuel additive that is supposed to clean injectors and increase the cetane rating. Should I continue to do this?

Exact same as I do, I use Hawes but to each his own............Mike

 

[Hay Dude]

I’d love to have time to warm up everything, but in my world, you gotta move fast. What I do is start up, wait maybe a minute, then idle slowly out of the tractor shop or through the field to get things lubricated, then being up the throttle.
On shut down, I idle a few minutes for the turbo charger. Been living this way for over 30 years of diesel operation. I have never had an engine failure, or turbocharger failure or really any engine related issue.
I have seen many an owner start up and go straight to 2000RPM and shut down immediately after a long day of work. I don’t recommend that.
You might want to include a lubricity additive to your fuel.
5 minutes of idling isn’t a big deal. You are not hurting anything. Frequent stopping and starting is not the best because of the extra work on your battery & starter. Diesel engine is higher compression and harder to get cranking.
If you don’t have a turbo, you can shut down after a brief idle-down. I have had lots of non turbo diesels I have shut down after merely dropping the rpm to idle, again zero engine issues.
With Diesel engines, the most important thing is fresh, clean fuel.

 

[SmallChange]

It's hard to beat having the manufacturer's own recommendations in front of you.

My manual says to start the engine with the fuel control set midrange. It does not call out a wait time before beginning operations. For shutting down, it says to set the fuel control all the way down, then do other things (parking brake, 3PT lower, etc), then turn key off. There's no time called out but it would take maybe half a minute to see to all the other things.

I have the idea that a cold engine would prefer to run fast rather than slow, though of course without a load. At least, the car I had with an automatic transmission wouldn't let the engine work below maybe 2500 rpm until the moment the blue "cold" light went out. The first mile or two of my morning commute, I sounded like a vacuum cleaner.

 

[Avenger]

Is it really necessary to run the engine for 3 minutes to warm it up? if so then why?

Yes. And probably better to let it warm up for longer, especially in colder times of the year. Why? Several different reasons, but mainly lubrication and wear. Think of how an engine works, oil sits in the bottom of the oil pan when the engine is not running. The oil is cold and thick, and doesn't move very well. Even at more moderate climates, oil is simply thicker than at operating temps. That oil needs to get pumped up and moved around the engine to lubricate it before stressing the engine by putting a load on it.

Another reason to let it warm up is wear. Along with lubrication, the engine will start to expand and seal its self up. This is kind of a gross over simplification, but think of the pistons and the cylinders. They are cold and the rings are not sealing very well. The engine starts and the hot exhaust starts warming up the pistons, right about where the exhaust port is. Now, before the engine is warmed up, you put a significant load on it. The exhaust temps rise quickly, expanding the side of the cylinder, piston, and rings. You'll get uneven wear and in extreme cases, scaring. Again, its an oversimplification, but hopefully starts to make sense.

And do I really need to idle the engine for 1 minute to cool it down? It's not that hot here usually and when we do have weather above 90 degrees I'm not gonna be running the tractor anyway.

Yes. And again, I'd do it for longer. This is more critical if your tractor has a turbo. The turbo on a diesel, especially after working hard, is going to be screaming hot. So hot that it will burn off any lubrication if simply turned off. The oil pump delivers oil to the turbo during operation. The oil flow suddenly stops flowing (because the engine is off), but the turbo is still glowing red hot, then any oil will simply burn away. This can cause serious turbo issues. Let the turbo cool down by idling the engine. If it cools too quickly, it can also crack!
Another good reason to let the engine idle before shutdown is to simply normalize the temps in the engine. Remember that piston ring with the hot exhaust temps? That is still the case here, the engine is hotter on one side, than the other. Let it simply idle for a few minutes before shutting it down. Simply helps minimize wear.

Is it a bad thing to shut off my diesel, shovel stuff into the loader, and then restart it after maybe 5 minutes to do more work? And to do this several times a day?

Again, following the advise above, I'd let it idle before shutting it off. Now, if you went out on a cool morning, fired it up, let it run for a few minutes, moved it slowly over to the stuff pile, and shut it off. There is probably nothing wrong. However, if you go out, fire it up, go mow at high RPM, do other heavy work with it for more than a few minutes, getting that engine really warmed up, pull up to the stuff pile, and simply shut it off, then yeah... thats not good.
Diesels can run, at an idle, for a very long time without any issues. Simply let it idle while you shovel your stuff.

I guess my last question for now is about fuel. I use the diesel fuel that comes from the pump right next to the gasoline pump at my local gas station. It's the same fuel that over the road vehicles use. I know it is low sulfur fuel and that 40 years ago engines were designed to use different fuels. On top of that, my engine was designed to be used in Asian countries, not the USA, and maybe their diesel was significantly different than the fuel available to me today. Because of this I am using a diesel fuel additive that is supposed to clean injectors and increase the cetane rating. Should I continue to do this?

Ah, the fuel question. This question has been asked and answered many times over the last several years. To be honest, diesel is diesel. And in your case, with your 40 year old diesel engine, you can run pretty much anything. However, I'm personally not a fan fuel additives. If you get clogged injectors, its not hard to replace them. You're more likely to get a clogged injector from particulates in the fuel and your tank than you are from deposits left behind. Make sure you change your fuel filter often. I'll probably catch some hate for saying this, but I believe that most fuel and oil additives are snake oil. The big question is dyed or clear diesel. There really isnt any difference, and if I were you, find some dyed diesel for your tractor. No reason to pay the State even more taxes.

Hope this has answered your questions.

 

[Jerry/MT]

Recently I bought my first diesel engine. This 40 year old engine came complete with a 40 year old Yanmar YM2310 tractor wrapped around the engine.
The manual says to pull the throttle handle all the way to full throttle, pull the decompression knob out and crank the engine until it starts. Once it starts set throttle to 1500 RPM or lower and let it run for at least 3 minutes before using the tractor. When stopping the engine it should be run at an idle for 1 minute to cool off before shutting down.
I have questions now about how to run this engine. I live just north of Seattle so the temperatures the engine will experience will be pretty moderate most of the time. Is it really necessary to run the engine for 3 minutes to warm it up? if so then why? And do I really need to idle the engine for 1 minute to cool it down? It's not that hot here usually and when we do have weather above 90 degrees I'm not gonna be running the tractor anyway.
I see folks who let their diesel engines idle away for long periods of time on a pretty regular basis. Not just big trucks but pickup trucks, backhoes, excavators, and small engined equipment like my tractor. I shut off my gasoline engined Case 580 CK backhoe rather than let it idle for more than a few minutes. Is it a bad thing to shut off my diesel, shovel stuff into the loader, and then restart it after maybe 5 minutes to do more work? And to do this several times a day?
For the next couple days I will be using a rock rake on an area I will be planting with grass. After a few passes with the rake I sort out and shovel all the rocks into the loader and then dump all the rocks into a hole I dug with my 580CK for this purpose. It takes 5 to 10 minutes to do this shoveling and sorting. I don't like having to let the diesel idle while I sort and shovel. So that's why the above question is asked.
I guess my last question for now is about fuel. I use the diesel fuel that comes from the pump right next to the gasoline pump at my local gas station. It's the same fuel that over the road vehicles use. I know it is low sulfur fuel and that 40 years ago engines were designed to use different fuels. On top of that, my engine was designed to be used in Asian countries, not the USA, and maybe their diesel was significantly different than the fuel available to me today. Because of this I am using a diesel fuel additive that is supposed to clean injectors and increase the cetane rating. Should I continue to do this?
Thanks,
Eric

In my opinion, any IC engine should be allowed to idle for a few minutes before being put under load. That's mainly to make sure the lube oil is starting to circulate.
From a warm up stand point, diesels are different than spark ignition (SI) engines. Spark ignition engines run within a relatively very narrow range of fuel/air ratios and therefore the peak cylinder temperatures are relatively constant. Power is controlled via the throttle plate regulating the airflow. SI engines naturally warm up quicker without load.
Diesels, on the other hand run with an unrestricted intake and power is controlled by fuel flow so the diesel runs over a wide range of fuel/air ratios. This means the peak cylinder temperatures vary with power output. It takes a long time to warm up an idling diesel on the typical tractor. (The Powerstroke diesel on my F350 uses an exhaust throttle plate to increase fuel air ratio on cold start up to facilitate warm up.) The best way to warm up your diesel tractor is at moderate load until it starts to come up to temperature.

I also believe it is better to let any IC engine idle for a minute or two before shut down. If you have a turboed Diesel, let it idle for at least a minute after full load operation. This allows the internal turbomachinery to cool down and not rub on the external casing leading to poor performance and possibly damage. Also many turbos rely on the engine oil pump for lube so you want the turbomachinery to slow down before the lube supply is cut off.

 

[CobyRupert]

There’s no throttle plate in a diesel, so it takes in the same amount of air per revolution at idle that it does revving or working hard. The compression cycle creates heat, but I believe it’s the fuel, when working, that will warm the engine faster than just pumping cold air through the motor with an idle amount of fuel being burnt.

 

[Diggin It]

Is it a bad thing to shut off my diesel, shovel stuff into the loader, and then restart it after maybe 5 minutes to do more work? And to do this several times a day?

That can be hard on batteries and starters. It can run a battery down since it takes a lot more power to start an engine repeatedly than some charging systems provide in short duration runs.

 

[Have tractor did travel]

I agree with all of the above. Gently. That's the way I treat my vehicles (tractor's included). The only thing I'd add - I enjoy working outside on my farm, listening to the birds, wind, etc. When I stop the tractor to dismount and work on the ground, I shut off the tractor. Batteries and starters may be the price I pay for doing that, but the pleasure exceeds the cost. I've got 1200 hours on the tractor I've had since new, and still with the original starter. Replaced one battery since 2009 - doesn't seem to be too much of a cost to work without the sound of engines running.

 

[Tinhack]

I'd lean to the cautious side. A 40 year old running tractor is still running because the previous owner(s) followed the operating and maintenance suggested in the manual.