M110gx: You guys may be my last resort: Not even Kubota can fix my problems.

[instyle555]

Question about this....

What on earth could the laptop 'forced' regen change that would allow the regen process to proceed. I mean, it dies with both an auto and a parked regen, but as soon as a forced regen by laptop is done....voila it works. Ye

 

[CobraTom]

Question (for everyone): Does his model have a common rail injection? If the DPF regen needs more fuel to operate in regen, could he have a bad injector? I could see a correlation between a cycling RPM and a bad injector when in regen if the computer tells the injector to stay "on" longer than normal and it sticks or leaks. Could that be a culprit? Could be more common with a common rail engine.

What do you guys think?

RGAZ

Not possible. The computer is constantly measuring rail pressures and if a injector does not cycle properly it would post a code. Piezo injectors and CR computers are so advanced the tech can perform a relative compression test to see if there is a bad injector or bad cylinder just with a single button on his laptop.

 

[CobraTom]

the tractor does not work hard at all; the hardest it will ever work is when I am driving full-tilt-boogy down the highway. So I know temps will stay cool causing more regens.

This is your problem. You are not running the tractor hard enough. I am betting the DPF is prematurely clogged from low rpm soot. This could be in combination or separate of a bad temperature sensor.

Forced regen is just that, a large amount of safety measures are turned off because the assumption is the tech is present and testing the system to find a fault. I do not believe the forced regen was ever intended to be run unattended.

 

[MHarryE]

Parked regen above zero C should keep the engine between 1500 and 1550 rpm. This is from my WSM which covers M100GX through M135GX.

The DPF parked regen required light is the one with a crankcase symbol having an exclamation point in it. Normally this light is off. If it starts blinking the conditions for an auto regen (plugged levels 1 or 2) are past and a parked regen (level 3) is required.

If the light is on steady then the PM is at level 4 or 5. If it is at level 4 it can only be regenerated using diagmaster (dealers computer software package).

If the parked regen cannot be completed, the DPF must be replaced.

 

[MHarryE]

If the dealer has not already provided, here is the check list for regen.

 

[MHarryE]

Another thing - the system has 4 sensors on the DPF. The main sensor is a differential pressure sensor on the DPF portion. It determine whether the filter is plugged to condition 1, 2, 3, 4, or 5. There are also temperature sensors DOC inlet, DPF inlet, and DPF outlet that the book says the ECU uses to determine the post injection pulse that feeds the DOC to burn off the soot in the DPF.

The temperature sensors are tough to check because you need to check resistance at 200 and 650 degrees (C of course). Same thing with the differential sensor - no way to test that except the voltage should be around 5 volts at 2 of the 3 terminals - terminal to ground.

 

[The Fred]

I wonder if the temp sensors are the same part number as I don't know but if 2 are the same try swapping them with each other.

Also turbochargers don't have to have boost problems to fail, most oiling issues are because the centrifugal seal in the exhaust side gets plugged with crap then leak out the rear polluting the CAT or is your case the DPF.

Kubota can't fix the problem because the system has not set any codes for them to see. I see this with engines that won't set readiness tests for emissions because one part of the system is out of whack but not enough to set a code.

I think M Harry has the best advice for you.

Here's before and after from one I cleaned.

Anyway I'll go on, a good friend bought a new M105ish machine in 2012. He had nothing but issues with the hydraulics. They would overheat enough actually to burn the paint on the pump within a few hours of getting it back. Dealer had it over 35 times from what he told me. Dealer then got Kubota rep involved in fact they sent a guy here to fix the machine. I believe he told me they hung 3 or 4 sets of new pumps on the machine to repair it. The last time he got it back I told him to use an infrared gun to check how hot the pumps were after a short use. He said over 400f. They hauled it off again and to everyone's amazement they actually found that from the factory the oil cooler was plugged. It took the dealer, with Kubota corporate help almost 5 years to figure it out. My friend got the machine back after the final repair and told me the whine noise of the hydraulic system was unbearable, he threatened with a lawyer and they actaully bought him a new M108 (I think because I don't know my larger tractor model numbers). He loves the new one.

My point here is that even though Kubota corporate is supposed to know what they are doing sometimes they simply don't.

Once there's an actual fix for your regeneration issue chances are Denso will modify the software that will narrow the parameters to set a fault code before the problem gets that bad for whatever is causing the issue so the next guy with the same issue will get his machine fixed sooner than you haven't. Unfortunately you are the lab rat.

Here have at it because this is what I would do.
Kubota tractors – deactivation of EGR and DPF already possible / Chiptuning AGROTRONIC

Regards, Fred

 

[instyle555]

Thinking about this more and more - I think it must be electrical (wire/sensor). It won't regen on its own, but it will with the laptop forced regen. To me this seems like the laptop changes a perimeter or something and it goes through with no problem.

Or.....is it possible to get ignition inside the DPF and thats why the EGT2 spikes to 850? I mean, if it ignited and burnt what ever crap it could, then perhaps the second regen would not ignite and the problem of EGT2 overheat would not be there anymore. By that account, it is coincidence that the laptop forced regen works....as it is always done after a failed regen.

 

[Diggin It]

Can they disable that entire process in programming temporarily (or not ) to see if any other problem shows up that might be causing this one?

 

[MHarryE]

The temperature sensors apparently have the same mounting meaning thread size, but the WSM states to be sure not to mix them when replacing the DPF. The 850 degree temp - does Kubota say if that is even possible? That is 250 higher than anything my nephew and I have ever seen. The temperature is controlled by pulse 4 of the injectors. Things are really going wrong here. If we are talking the temperature at the same sensor we see at the instrument panel, I suspect the high heat has damaged the filter substrate. As I mentioned Kubota had no qualms about replacing the DPF on mine when it got oiled but of course you have a different representative. He might have a tighter customer loyalty budget than mine had and therefore is not as prone to spend money to keep the customer happy. In my case keeping me happy resulted in replacing the M135GX with a M7-171 KVT at double the list price so keeping me happy had a significant payback.