I hate my new L3901

[bgk]

comparing gas and diesel is like apples and oranges. running the tractor at high rpms causes the wear and tear. in the future the emission system is going to foul, eventually the dpf will no longer be able to clean it's self. you need to check for contaminated oil after regin, some fuel can back wash down the exhaust and puddle on the valve during the intake and compression stroke

If operated correctly the DPF won't plug up (requiring removal and sent to a local diesel shop with a cleaning machine that essentially blows it out with compressed air. In extreme situations they need to be baked). They are run successfully on OTR trucks for 100's of thousands or even million+ miles. It's a different application, but if you run the machine correctly the regens will work. Lots of idle time, low RPM usage and short jobs will negatively impact it.

 

[bham]

If operated correctly the DPF won't plug up (requiring removal and sent to a local diesel shop with a cleaning machine that essentially blows it out with compressed air. In extreme situations they need to be baked). They are run successfully on OTR trucks for 100's of thousands or even million+ miles. It's a different application, but if you run the machine correctly the regens will work. Lots of idle time, low RPM usage and short jobs will negatively impact it.

that is what a 33hp tractor does

 

[bham]

Bham may be exaggerating, and I think no one outside Kubota has the exact details as to how the engine is controlled during regeneration. The owner's manual does warn that you can contaminate the oil with diesel if you interrupt regeneration. I am not sure exactly how that could happen. However in nearly 3 years with mine I see no indication that that happens during normal operation. These high pressure common rail engines get greater normal efficiency since the injectors can be programmed to spray diesel at more than one time during the power stroke. I don't know how this changes during regeneration. NOTE this is not how it is done in the B3350 where diesel is sprayed by a separate line into the exhaust stream during regeneration. What I am trying to say is that there are tradeoffs for the inconvenience of dealing with a dpf. They are nice engines IMHO.

the3301 is a homeowner tractor, cutting fire wood, finish mowing and moving stuff with the forks. there is no need to run at 2000+ rpm. leveling a flower bed next to the house in low and first gear requires lo speed. do you think the tractor needs to run at maximum capacity to do this job .




The L60 series allows you to monitor particle buildup in the dpf, and the greatest accumulation is the first 10 minutes as the engine comes up to operating temp. After that the speed at which particles accumulate is determined by rpm and load. You don't have to run it like you stole it every day. Days that you mow the meter runs backwards. Days you putter around with a landscape rake it may go up. The dpf filter is rated for 3,000 hrs. Mine will outlast me if I don't screw up. I don't see the engine wearing out either, but we won't have data to support that for some time. Makes me cranky when folks proclaim that x or y is true when data is simply not available.

I think the biggest legitimate beef people can make is that you have to pay attention and follow directions. Some folks just don't want to do that, and when as the OP complained, the system is not working properly, can't devote an hour or more to a regen when they have off tractor obligations.

the3301 is a homeowner tractor, cutting fire wood, finish mowing and moving stuff with the forks. there is no need to run at 2000+ rpm. leveling a flower bed next to the house in low and first gear requires lo speed. do you think the tractor needs to run at maximum capacity to do this job .

 

[bham]

some people think if you are not pulling a 6 row plow, you shouldn't have a tractor

 

[lugbolt]

the3301 is a homeowner tractor, cutting fire wood, finish mowing and moving stuff with the forks. there is no need to run at 2000+ rpm. leveling a flower bed next to the house in low and first gear requires lo speed. do you think the tractor needs to run at maximum capacity to do this job .

There is a need to run at 2000+. When that light comes on, idling around ain't gonna do anything but make matters worse. Times and tractors have changed, and we have no choice but to deal with the changes the best we can. That and tell your congresspeople that you don't agree with the way this is done. If enough people make it known that this stuff is a joke, maybe something will get done. "Maybe".

Here's what a DPF cleaning entails: https://www.youtube.com/watch?v=M_yjgEXvyqU

 

[lugbolt]

How does regeneration work?

First, there are sensors in the exhaust system that monitor EGT and exhaust pressure. The sensors tell the ECU when soot level gets excessive, and when conditions are right, the ECU will request the operator to do a regen cycle.

The cycle is pretty simple. While the engine is running, a tiny amount of fuel is injected at or near the the piston's bottom dead center, after the combustion cycle but near the exhaust stroke. Fuel is blown out of the engine and into the exhaust system. At the same time, the engine is also moving air. The fuel and air ignite in the DPF, which raises the temperatore of the DPF element to around 1100-1200 degrees F. At this temp, the soot is chemically changed to ash. Ash is currently considered harmless. Most of the ash is discharged out of the exhaust pipe, and no you can't see it. But you can sure feel the heat during a regen process. That is what the DPF inhibit button does. If you're in a hay barn or bush hogging in really dry grass, temporarily stopping the regen cycle isn't a bad idea to avoid fire.

How does fuel get into the crankcase? Piston engines all have some blowby. Some of the air and/or fuel will get by the rings-there is no way around it. A non DPF engine burns most of the fuel that is injected. A DPF engine, however, injects fuel that is not burned during a power stroke, so a small amount of it will get past the rings and into the oil. Especially on a cold engine. That is one reason that the L-01's will not regen if the engine temp is "cold" or "cool". It needs to be at or near operating temp, around 185-200 degrees F. At those temps, the pistons are hot, expanded as much as they are going to, and the seal is MUCH better than a cold engine. On that note, if a thermostat is stuck open, the engine won't warm up, and bad stuff happens. So the thermostat is now a big deal, where on the older stuff, they'd run fine without one or with a stuck one.

Someone mentioned the L2501. Yeah, it's a good tractor. Can it be turned up? Probably. But it's also governed to, I think 2200 RPM. So you're looking at a governor change. Because the governed RPM is low, the trans and PTO gear ratios had to be changed to compensate. So when you change the governor to allow 3000 RPM +/-, it will become extremely fast, and the PTO will over speed. Easily fixable if you know what to look for, but you'll have to split the tractor to do it.

 

[sheepfarmer]

the3301 is a homeowner tractor, cutting fire wood, finish mowing and moving stuff with the forks. there is no need to run at 2000+ rpm. leveling a flower bed next to the house in low and first gear requires lo speed. do you think the tractor needs to run at maximum capacity to do this job .

No. Nor do I think that you should run wide open throttle when it is unsafe or impractical. The thing that is different in these new tractors is that starting them is easy, and probably easy on the starter and other parts. So the big difference in operating from an old diesel is that you don't gain anything and will contaminate the dpf if you get off the tractor for coffee and leave it running at idle. And there also is no point in leaving it running at wot while you get coffee. The way I understand it, the tractor's computer calls for regen based both on the pressure change across the filter AND the amount of fuel used. So running at high rpm unnecessarily could also contribute to regen frequency (my unsubstantiated theory). The point is whether or not someone can run it at high rpm for 10 or 15 min when it is necessary for a regen. You don't have to run it that way all the time.

 

[Racer X]

Yeah,
I'll keep my 95 Powerstroke diesel too....

I think we need a pick up truck thread....

2001 Ram 3500, Cummins ISB 24 valve HO with 6 speed manual. Was the last pickup I will ever need to buy.

Just turned 135,000 miles today, time to rotate the tires and change the oil and filters again.

 

[Racer X]

The way I understand it, the tractor's computer calls for regen based both on the pressure change across the filter AND the amount of fuel used.

I was wondering how they were doing that.

I worked at a heavy truck manufacturer's research and development facility for a while doing product test and development. One of the projects I worked on was development of the early exhaust aftertreatment and the DPF. This was just before the SCR system went into development.

At the time, the systems (I worked on two different engine manufacturers systems) estimated DPF level of soot by looking at fuel consumption, hours run, miles traveled, and calculated when the DPF should be full enough to require a regen.

An engineer I met there that had been hired from the automotive side having worked at Ford told me they were using pressure drop across the DPF to more precisely predict the right time to initiate a regen.

Made sense to me. Now I'm only a mechanic, so what do I know, right?

So running at high rpm unnecessarily could also contribute to regen frequency (my unsubstantiated theory).

And this also adds up in my way of thinking.

 

[Racer X]

Here's what a DPF cleaning entails: https://www.youtube.com/watch?v=M_yjgEXvyqU

Working that product test and development gig the various DPF cleaning system manufacturers sent versions of their DPF cleaning machines for evaluation. We had Donaldson, OTC, FSX and a couple others I can't remember.

This was 10 years ago, and they hadn't started using a kiln to cook the filters yet.

I liked the FSX system the best.


https://www.youtube.com/watch?v=0PVSz-F2x6A

 

[skeets]

Now I wonder why, rather than do the regen thing, they havent follower the auto industry and used the urea injection like one so many cars and trucks

 

[Newlyme]

The DPF is a wear item. Not unlike an oil filter, trans filter or cabin filter. It's a fancy air filter that has the ability to clean itself up to a point. At some point there is enough ash left inside after all off the regens that it needs replaced. I am also a member of the TDI Club Forum and some of those guys are really gear heads over there. They have a thread specifically set up to collect DPF data and track when the DPF "needs" replaced. It's based upon the number, amount, of ash the computer calculates is in there. Light on the dash comes on, replace DPF. It's very simple but expensive. Volkswagen even has a special low ash oil that has to be used to slow the ash build up in the system. Don't know about Kubota oil requirements but I am curious.

 

[Racer X]

Now I wonder why, rather than do the regen thing, they havent follower the auto industry and used the urea injection like one so many cars and trucks

Automotive systems still have a DPF, and it does get a regen cycle, be it passive or active.

Even the systems that have SCR and urea.

 

[coachgeo]

... I am also a member of the TDI Club Forum....

Oh .... Hail to the TDI club Been a member there for decade or so myself as well.

 

[sheepfarmer]

Now I wonder why, rather than do the regen thing, they havent follower the auto industry and used the urea injection like one so many cars and trucks

Skeets the dpf filter takes out particles, the DEF converts nitrogen oxides into nitrogen gas, carbon dioxide, water, less harmful. Both systems are usually present. See picture in link below.


http://www.dieselforum.org/about-clean-diesel/what-is-scr

As for why DEF not in tractors, it is in some of the new big Kubotas, but lugbolt made the point that the DEF needs to be fresh, so a problem in vehicles that sit around . I don't know anything about that aspect. My truck is a 2003.

 

[lugbolt]

Less soot is created with the engine RPM high. More soot is created when engine RPM is lower and with a load against it. Think about the old diesel trucks going up a hill or pulling a big load. They'd lug them and the stacks would be rolling coal. Same principle.

The higher the RPM the more heat is generated. Heat is what causes the change from soot to ash. So let's say you're bush hogging, got the engine RPM up around 2500 RPM with a load. The tractor might want to regen but it will do it on it's own. Light comes on, while you work, then light goes out while you're still working. Nothing else needs to be done. Sometimes you may not even know it's in regen cycle, it just does it and it's done and you never even know it.

But on the other end of the scale, let's say someone uses their tractor to move snow with the FEL in sub freezing weather. Start engine, let it warm up at idle speed. You clear the stuff off with the engine RPM around 1200-1500. It doesn't generate much heat, and is being loaded at lower engine RPM, thus will need to regen sooner and more frequently because more soot is produced with little heat in the system to burn it off.

Yes there's times when it's not safe to keep RPM high. But if you can, it sure helps prolong regen frequency.

 

[sheepfarmer]

How does regeneration work?

First, there are sensors in the exhaust system that monitor EGT and exhaust pressure. The sensors tell the ECU when soot level gets excessive, and when conditions are right, the ECU will request the operator to do a regen cycle.

The cycle is pretty simple. While the engine is running, a tiny amount of fuel is injected at or near the the piston's bottom dead center, after the combustion cycle but near the exhaust stroke. Fuel is blown out of the engine and into the exhaust system. At the same time, the engine is also moving air. The fuel and air ignite in the DPF, which raises the temperatore of the DPF element to around 1100-1200 degrees F. At this temp, the soot is chemically changed to ash. Ash is currently considered harmless. Most of the ash is discharged out of the exhaust pipe, and no you can't see it. But you can sure feel the heat during a regen process. That is what the DPF inhibit button does. If you're in a hay barn or bush hogging in really dry grass, temporarily stopping the regen cycle isn't a bad idea to avoid fire.

How does fuel get into the crankcase? Piston engines all have some blowby. Some of the air and/or fuel will get by the rings-there is no way around it. A non DPF engine burns most of the fuel that is injected. A DPF engine, however, injects fuel that is not burned during a power stroke, so a small amount of it will get past the rings and into the oil. Especially on a cold engine. That is one reason that the L-01's will not regen if the engine temp is "cold" or "cool". It needs to be at or near operating temp, around 185-200 degrees F. At those temps, the pistons are hot, expanded as much as they are going to, and the seal is MUCH better than a cold engine. On that note, if a thermostat is stuck open, the engine won't warm up, and bad stuff happens. So the thermostat is now a big deal, where on the older stuff, they'd run fine without one or with a stuck one.

Here is a picture modified from my WSM to illustrate what lugbolt and I have been saying about the common rail injection system and regeneration:

The peaks in fuel injection A, B, and C are during the main burn. D is called by Kubota a "post injection" and is used for regeneration. This fuel passes with the exhaust first into the DOC, diesel oxidative catalyst, (like a catalytic converter), and a heat- producing reaction there with the diesel and other materials further heats the exhaust which then passes into the DPF filter. It is so hot that it incinerates the particles trapped on the ceramic filter. The DOC and the DPF filter are mounted in one "can", in series, if you are looking for it on your tractor.

My assumption is that peak D, the post injection of fuel, does not occur until regeneration is started. A is supposed to reduce the noise and also Nitrous oxide, B is the main burn, C is a diffuse combustion to reduce particulate matter.

 

[bham]

damit, i guess i jinxed my self, 81 hours and regin again, so far about every 15 hours. i was coming back from the back of my property and the light came on so i drove around in circles for 20 minutes at about 2700 rpms looking for a golf ball that i lost

 

[bham]

Here is a picture modified from my WSM to illustrate what lugbolt and I have been saying about the common rail injection system and regeneration:

The peaks in fuel injection A, B, and C are during the main burn. D is called by Kubota a "post injection" and is used for regeneration. This fuel passes with the exhaust first into the DOC, diesel oxidative catalyst, (like a catalytic converter), and a heat- producing reaction there with the diesel and other materials further heats the exhaust which then passes into the DPF filter. It is so hot that it incinerates the particles trapped on the ceramic filter. The DOC and the DPF filter are mounted in one "can", in series, if you are looking for it on your tractor.

My assumption is that peak D, the post injection of fuel, does not occur until regeneration is started. A is supposed to reduce the noise and also Nitrous oxide, B is the main burn, C is a diffuse combustion to reduce particulate matter.

also remember the dpf is vertical of the engine,if it was below the head there would be no contaminated oil from regin. but it probably wouldn't meet emissions

 

[Dieselbob]

The DPF is a wear item. Not unlike an oil filter, trans filter or cabin filter. It's a fancy air filter that has the ability to clean itself up to a point. At some point there is enough ash left inside after all off the regens that it needs replaced. I am also a member of the TDI Club Forum and some of those guys are really gear heads over there. They have a thread specifically set up to collect DPF data and track when the DPF "needs" replaced. It's based upon the number, amount, of ash the computer calculates is in there. Light on the dash comes on, replace DPF. It's very simple but expensive. Volkswagen even has a special low ash oil that has to be used to slow the ash build up in the system. Don't know about Kubota oil requirements but I am curious.

AS long as the DPF has not cracked or melted down, it should be able to be removed, professionally cleaned and reinstalled. I have class 8 truck DPFs baked and ultrasonic cleaned every week for about $300 VS $2000 for new unit.