heavy exhaust smoke w/ decreased power

[Luke009]

Hi all.
2017 Kioti CK3510 owner here. At about 23 hours, the tone of the engine suddenly lightened up with some loss of power and the exhaust started smoking heavy black smoke. No light came on the dashboard. After calling the dealer, we agreed to try do a forced regen, which took the standard 40 min., and during which the smoke eventually cleared out. They also checked the OBD codes and nothing abnormal was found. We left it that I should be running higher rpms, as I was running the tractor mostly in economical mode at the 1800 mark. Well, why that mark's there and why can I not save engine/gas, that's another question.
Yesterday, at 44 hours, having been running 2100 average rpm, the event reoccurred. In need to get the tractor out of the work site I just reved it higher to make up for the power loss and a minute into it the smoke cleared out. I haven't started it since.
I do understand the carbon build up issue but we're talking very few hours here, with babying or light workloads, and rpms in the middle of the range, even at their recommended marks. Air filter is clean and I cleaned it after every dusty session. I'm rather deflated at the possibility of something being wrong with what I thought was a good (and expensive!) buy tractor. Ideas or shared experiences would be appreciated.

 

[southernAL]

My guess is keep running it with the rpms up high.

 

[xcgreene]

I would say you certainly have an issue here. Definitely too little air or too much fuel but for what reason? sensor issue related to regen perhaps, I have little experience with the kioti regen system at this point in time, but maybe another member on here will chime in with more insight.

 

[DieselBound]

On the NXes there's two regens, one is a passive and one is not. The passive one you can continue to run the tractor, though RPMs need to be kept above 1,700. The full regen wants you to park and let it run through its cycle. Each regen type has its own dash light. If a dash light isn't coming on then the dealer needs to figure out why. Your hours seem about right for regens. If you don't run long (warmed up well) and you have idling time then regens are going to happen at shorter intervals. I'm wanting to say that I run about 30 - 35 hours between regens: I do idle a bit, though not on a regular basis; and mostly after the tractor is started its active for a fair amount of time (and the weather is warm, so warm-ups are pretty quick).

I don't recall seeing white smoke during regens, but for sure there's a "distinctive" smell.

 

[Luke009]

Eventually, after the heavy smoke and decrease in engine power, the regen "underway" light came on. Had to deactivate as I had to stop the tractor shortly and leave. This morning did a manual regen, then operated the tractor for a bit, all seems back to normal. Dealer says the short time intervals between the regens are normal. Also says auto regen could kick in without the warning light coming on, and you can continue working through the 40 min. process. Issues remain unexplained: why do I get the heavy smoke, as if massive soot has built up in the dpf, but no regen "warning" light? And why do I lose some power with it and for an undetermined time afterward?

 

[Egon]

Start varying the RPM.

 

[DieselBound]

Look in your operators manual to see what it says about regens. I highly doubt that it says that the light may or may not come on. I'm not so sure the dealer knows what's what.

You should smell the regens occurring. If you have decreased power, no regen light and no regen odors then you're NOT having a regen happening.

 

[dadster4]

There was another thread with similar issues...a temp sensor in the DPF wasn't reading correctly, which threw off the computer's settings for fuel mixture at regen, which in turn created the smoke issue. Problems I have seen in most threads concerning regen cycles seem to be due to operating at too-low rpm's. Run it no lower than 2400, and 2600 or so when doing heavy work, you will see your time between regens increase.

 

[DieselBound]

But, if there's no regen light coming on then that means that the computer isn't triggering one, that or there's some problem with the lighting of the dash indicator.

I agree that if there's an issue in sensing DPF build-up and the computer isn't running a regen as it should be then when it does a regen things are going to smoke more.

Running 2,400 to 2,600 RPM. If one is so worried about regens that one has to constantly run at this high of an RPM then perhaps they might consider a non-DPF machine? No way I'm going to be running my tractor that high all the time, it's a waste of fuel (yes, it'll keep the DPF cleaner, make my teeth whiter etc). I can tolerate a (passive) regen every 35-40 hrs or so: I am trying to recall whether I've had more than one full regen (park and let it do its thing) in 215 hrs- THIS regen isn't fun, and if it were doing this every 35-40 hrs I would NOT keep this tractor (or anything else that did this). The good is that it ain't happening frequently (I look to run at least 1,800 RPM), AND, it's nice to have a less stinky tractor (my cars and truck don't have DPFs, but when running them I'm ending to be outpacing the exhaust).

 

[Luke009]

I agree with DB that 2400 rpm on a constant basis is high, loud to your ears, and wasteful. I would think that 1800 rpm is plenty for light work. Dealer says this issue is across the industry but does it make sense to have to run a tractor high in order to avoid often regens? If I knew that would be the case I wouldn't have bought this but what non-dpf choices does one have in this power range? I'll see what happens from here on and if indeed the regens will happen automatically and if I'll be able to work through them and without decreased power. Having to stop 40 min. again in 20-30 hours for a manual regen will really throw me off.