Kubota B3350, Diesel Particulate Filter (DPF) Regeneration Issues.

[John Bottcher]

I have a Kubota B3350, which has the Diesel Particulate Filter (DPF) that has to be parked and regenerated too often.

Has anybody out there had any luck with removing or disengaging the DPF? I live way out in sparsely populated county far away from any cities or areas with polluted air, so a little particulate wouldn't be measurable (a lot less than the dust I kick up just driving it!). Seems to me that just driving with a normal muffler would work without the hassle of doing a parked regen every 20 hours or so. Also how much air pollution is emitted by the the regen process? Which seems like a waste of fuel too! Not to mention down time.

I'm seriously thinking about switching out the DPF with a standard exhaust system. Has anybody done that, and if so, were there any problems?

 

[nybirdman]

I don't think it is as easy as swapping the exaust out;computer controlled?

 

[RickB]

You will have a non-functioning tractor if you remove the DPF and it’s associated sensors without making changes to the fuel system operating software. You should not have to perform parked regents if the system is working properly. That said, the original software used in a B3350 was quite problematic. If your engine ECU has not been updated with current software (in say the last 6-8 months) it would be worth having this done. Remember the emission system is covered by warranty for 5 years by EPA mandate.

 

[SDT]

I have a Kubota B3350, which has the Diesel Particulate Filter (DPF) that has to be parked and regenerated too often.

Has anybody out there had any luck with removing or disengaging the DPF? I live way out in sparsely populated county far away from any cities or areas with polluted air, so a little particulate wouldn't be measurable (a lot less than the dust I kick up just driving it!). Seems to me that just driving with a normal muffler would work without the hassle of doing a parked regen every 20 hours or so. Also how much air pollution is emitted by the the regen process? Which seems like a waste of fuel too! Not to mention down time.

I'm seriously thinking about switching out the DPF with a standard exhaust system. Has anybody done that, and if so, were there any problems?

Probably not a good idea at this time.

Verify if your 3350 is COMPLETELY up to date.

I have had no issues with my 3350 after it was updated to current specs. Caveat: 22 hours.

That said, I remain skeptical, knowing that Kubota is currently working to replace the mechanically injected B3350 engine with a much more modern common rail injected engine.

Stay tuned.

SDT

 

[Rmart30]

I have a Kubota B3350, which has the Diesel Particulate Filter (DPF) that has to be parked and regenerated too often.

Has anybody out there had any luck with removing or disengaging the DPF? I live way out in sparsely populated county far away from any cities or areas with polluted air, so a little particulate wouldn't be measurable (a lot less than the dust I kick up just driving it!). Seems to me that just driving with a normal muffler would work without the hassle of doing a parked regen every 20 hours or so. Also how much air pollution is emitted by the the regen process? Which seems like a waste of fuel too! Not to mention down time.

I'm seriously thinking about switching out the DPF with a standard exhaust system. Has anybody done that, and if so, were there any problems?

John can you go into more details on whats happening with your machine?

 

[sandyc]

Check with kubota to make sure you have the total update package. I have a low s/n unit and have only had one parked regen in 160 hours. It regenerates every 15 hours or so and the only way I know is the dash symbol lights. I run at 2000 rpms most of the time. Also I push the auto regen button whenever I start the tractor.
My update included a new generator and larger left side of the hood to accommodate that. The ecu was updated. Magnet attached winter front. Additional insulation around the blower pipe. The dealer told me he had to buy the update items and they cost over $1,000 per tractor.
The tractor updates in the winter blowing or plowing snow when the temp is below zero. My heat gauge shows three bars and sometime 4 when it’s regening in the snow.

 

[SDT]

John can you go into more details on whats happening with your machine?

Not John, but here's the latest B3350 regeneration information that I have. This information supersedes my 02/2018 post above. Highly abbreviated version.

I can say unequivocally that the regeneration issues with the B3350 and high end F series mowers using the same engine are NOT fully resolved.

My 3350 is a late SN, 2018, still on the Kubota shipping frame in May of 2018, and not an aged inventory unit. I have been informed by multiple folks including a Kubota regional service representative, that my unit has all of the latest upgrades and fixes. More on this later. Considerable inspection and verification of such was performed prior to delivery last June.

My unit now has about 30 hours on the clock. It has attempted to perform running regeneration operations twice since delivered. Both times it shut down abruptly and would not restart. It is currently at the dealers awaiting authorization from Kubota to attempt further work.

It was trucked to the dealer on May 20. Coincidently, the (new) Kubota regional service representative was at my dealer on the 21st. While there he spent considerable time diagnosing my 3350 and an F series mower with the same engine. The reformer on the F series was replaced and it was sent back to the owner. Time will tell.

No one can find anything wrong with mine. Both times that it failed it stored the common OT code but did not display an error code in the display. After 30+ minutes cool down it will start but my attempts to perform a parked regen failed because the instructions in the owners manual are not correct. Turns out it was trying to perform a (non parked) regen at the time. The instructions in the owners manual are confusing and incorrect in at least one area. Live and learn.

I informed the Kubota representative that I was aware that Kubota is planning to replace the direct injected engine in the B3350 with a common rail injected engine (knowing that he would not be able to speak to this), and asked if anything more was being done by engineering to address the as yet unresolved issues with the current design. It appears that current status is a wait and see approach to see if issues have been resolved (They aren't.) This experimental approach is problematic as it costs customers money and time. Kubota does not pay transportation for warranty work so I must. I have now paid to have it trucked to the dealer (and back) to have this issue repaired. Paying multiple times to repair the same problem is unacceptable to me.

Current plans for my machine are to send the injector pump and injectors out to verify that there is nothing wrong with either. I believe that this is a waste of time and money but apparently Kubota wants it done. Only after this has been done might they replace the reformer. I believe that replacing the reformer is much more likely to solve the problem with my tractor but remain skeptical.

I was told that the design of the reformer was changed near the SN of my tractor. I was also told that SN records vis a vis engineering changes are not always precise. Moreover, I was told that the SN of the reformer on my tractor was just about impossible to read. Twice I have asked that the reformer be changed on my tractor but Kubota is not yet willing to do this because "It is a $5,000 part." What! Thanks, feds.

Since the 21st, nothing has been done to my tractor because of other work in the shop that was booked earlier. Fair enough.

More to come.

SDT

 

[RGAZ]

SDT,

I am very curious what you find. I have the same problem with my B3350 but I find that as long as I hold the rpm high when regen and NEVER BOG it, it will eventually regen. I have 150 hours on mine and its pretty consistent. If I mess up and the engine speed drops, it dies and cannot be started for 20+ minutes just like yours. My dealer is more hostile so I gave up taking it back and forth as they act like uninformed monkeys every time I show them the problem. If you find something of value i am all ears.

If they do not resolve it, I will be cutting my DPF off, busting out all the filter, and welding it back together so the sensors still work and it looks like it has a filter. Just waiting for the warranty to end.

RGAZ

 

[sixdogs]

SDT,

I am very curious what you find. I have the same problem with my B3350 but I find that as long as I hold the rpm high when regen and NEVER BOG it, it will eventually regen. I have 150 hours on mine and its pretty consistent. If I mess up and the engine speed drops, it dies and cannot be started for 20+ minutes just like yours. My dealer is more hostile so I gave up taking it back and forth as they act like uninformed monkeys every time I show them the problem. If you find something of value i am all ears.

If they do not resolve it, I will be cutting my DPF off, busting out all the filter, and welding it back together so the sensors still work and it looks like it has a filter. Just waiting for the warranty to end.

RGAZ

Would that work? Is it a foolproof fix?

 

[SDT]

SDT,

I am very curious what you find. I have the same problem with my B3350 but I find that as long as I hold the rpm high when regen and NEVER BOG it, it will eventually regen. I have 150 hours on mine and its pretty consistent. If I mess up and the engine speed drops, it dies and cannot be started for 20+ minutes just like yours. My dealer is more hostile so I gave up taking it back and forth as they act like uninformed monkeys every time I show them the problem. If you find something of value i am all ears.

If they do not resolve it, I will be cutting my DPF off, busting out all the filter, and welding it back together so the sensors still work and it looks like it has a filter. Just waiting for the warranty to end.

RGAZ

When this last happened, the engine was at WOT.

After mowing for about 10 minutes, I noticed that the regen lamp was on. The engine was at about 2,100 RPM at the time and I immediately pullet the throttle to WOT. Continued to mow for about 5 more minutes until the area that I was working on was finished.

Wanted to return to barn now but decided to waste time and fuel with make work to allow the regen process to complete. Left throttle at WOT, raised mower, turned FWA off and headed to another area where I could waste time and fuel making work. Annoying.

Left PTO engaged to avoid abusing PTO brake by turning PTO off while operating rotary cutter at WOT. Afraid to reduce throttle.

Engine abruptly shut down at WOT with rotary cutter (bush hog type) at full speed. No beeps, warnings or error codes. Blades slammed forward and jammed. Very annoying. Engine would not restart until after lengthy cool down. Fortunately tractor on slope so could push out of road.

Kubota wants to check pump and injectors. I believe this to be a waste of time but not my decision. Believe replacing expensive reformer best bet to correct or at least improve situation, but very skeptical. Frankly, do not believe that it can be made reliable with current design.

Stay tuned.

SDT