Hi all, newbie here, greetings from Canada I normally find what I'm looking for without posting, but this one's got me stumped. Background: Machine is a 2014 T750 with a Tier 4 interim V3800 from Kubota. I bought the machine with 4800 hours on it from a Ritchie Bros. When the machine arrived it had a pretty good rod knock, so we tore the engine down and rebuilt completely. Cylinders were bored .020 over and all OE Kubota parts used. With the engine reinstalled I'm getting issues with DPF. Initially it was throwing an E523601-00 (Exhaust Gas Temperature Sensor Fault. At the same time as throwing this code it would shut down, and inhibit starting till either I unplugged the 3 EGT sensors on the DPF or let the machine cool for 30-45 min. I resistance checked the sensors and found one of them to be reading erraticly, so it was replaced. Issue still persists, and the machine goes into regen (stage 1) much more than I think it should. The only thing I hadn't gone through was the DPF. So as per the dealer's suggestion I removed the DPF and had it cleaned. I just got it back in the machine today, and ran it for a good 45 min or so. It didn't shut down, but the machine still attempts to regen much more than it should be, to the point where I hit the manual override to keep it from going into that mode. As of now it's throwing two codes. E523602-00 (DPF Fault) and M5902 (DPF inhibit regeneration switch error ON). The first code didn't show up until about 2 minutes before I shut the machine down. I'll be having the dealer coming out Monday to plug in and reset the soot level via Diagmaster, as well as do a supply pump calibration and see if we can't figure out why it keeps throwing codes. Any input anyone would be able to offer would be greatly appreciated!! I've already gone through and done the voltage checks found in the manual for the EGT sensors, they check out fine. Thanks in advance!
how often is it going into passive regen?
What condition are the injectors? What about blowby? Something might actually be sooting up the DPF faster than normal. If it is possible, you might have to run it temporarily with open exhaust to watch for smoke.
Check the turbo? Is it using more oil as it should. You got to much soot goin into ur emission system
I agree with Birken. When the engine was rebuilt was it run in on a dyno? Back when I did a bunch with engines it used to be that you had to get a pretty good load going on the engine to get the rings to seat in on the liners. With the variable flow hydraulic systems that run these machines these days it seems possible that it isn't easy to get a big load to seat in the rings like we did in the past. That makes for more blow by and the positive crankcase ventilation systems pull that right back into the intake to be burned and exhausted into the DPF. Is there anyway to disconnect the plumbing to the crankcase ventilation system and check crankcase pressure under full load?
Everybody is right.. How are you running it? at idle?? You gotta run the snot outta it from the git go.. under a load.. put a bush hog or something behind it & run.. it should clear up in an hour.. OR what some people do is push a tree.. NO KIDDING.. put the front end against a tree, drop'er in gear & "mash the gas", so to speak.. IF your not getting the engine "hot enough".. the regen will keep doing its thing.. burning off the residual carbons.. Good luck..
Thanks for the input guys. When I rebuilt the engine I flashed it up, idled for 5 min to warm up while I checked for leaks etc, then ran it hard for an hour. By hard I mean WOT, bogging it down on grade and pushing etc. On cold startup it burns off condensation for 20 seconds, then clears. No smoke. When I rebuilt the DPF, I ran it open. No smoke. Injectors were tested. 3 were ok, 1 was flagged for high return rate but normal delivery rate. They suggested replacement but said it was ok for continued use. Injectors are 1200 apiece and aren't currently rebuildable.
Turbo is fine. Not blowing oil I will pull the ccv line and see if its blowing oil
If I don't hit the override button, it'll try to regen every few minutes, and runs for 15-20 seconds. Unless I'm mistaken, passive regen is when the machine is running hot enough to burn the soot off the DPF by itself. Active regen is what happens when it displays the "Regen" message, and when the over-ride light comes on. There are 6 different levels of regen, from passive all the way to active level 5. All I've seen is level 2 regen once when we bought the machine, and level 1 is what keeps popping up now. The last thing I'm going to be checking is the manifold pressure differential sensor. I believe it's what the ECM uses to determine whether it needs to go into regen or not. It just dawned on me today that it could be causing issues without throwing codes, so I'll be checking that in a few minutes.
Update: I went through the voltage checks for the differential sensor. It's fine. Ran the machine up to temp and checked the blowby coming from the valve cover...nothing. It's fine as well. I let it regen for a few minutes till it cleared the message, but it's still holding the DPF fault code. Bobcat will be getting called tomorrow to come do a little plugging in. I have a different set of injectors that we had purchased before we realized the whole compensation code thing. They're out of a M9960DTC which uses the ag version of the same engine (basically the same engine except it has a balance shaft and a different front dress). We had them flow-tested at an injection shop along with the originals, and there was 2 good ones. If they're the same approximate rate as the ones in there I may swap the bad one for one of them.
typically i see passive regens every 28-30 hours. stop hitting the override, and let the engine do what it wants to do. it may be a good idea to have bobcat plug into that engine and see whats going on. if you've been swapping injectors around, that could be causing some of your problems. i dont recall if the kubotas have the injectors coded to each cylinder or not, but if the injectors are coded to an individual cylinder and NOT put back in the same hole, it may cause some issues.
Somebody correct me if I am wrong, this is all still new, but I think all HPCR injectors from all manufacturers are individually coded now...
at 1200.00 apiece.. I would think so..
i assume they are too, but i havent seen a kubota injector, and it's been a while since ive looked at the kubota software....
Thanks for the input guys. Bobcat tech is currently here. He's spent the last hour or so trying to figure out the password for his diagmaster account.....not ideal. He pulled codes, the DPF fault code logs whenever the ECM records more than two DPF cycles in the space of 30 minutes. He's working to resolve now but it looks like I may be swapping injectors. As for the HPCR injectors being individually coded...yes they are. Each injector has a compensation code that accounts for 2-5% of its fueling rate. I just got the flow specs from all 8 injectors that I have. 3 of the original set are ok, the one in cylinder 4 is overfueling. I have one injector from the extra batch that tested in the same range as the original 3. As per Denso USA, there is no rebuild program available, however they do suggest batch testing injectors to find a group that are the same, then using the same compensation code for all 4 injectors. As long as they're the same tested flow rate, there should be no issues. Not ideal, but not really any other choice other than fork out 1200+
Last update. Thankfully Had the tech out as I mentioned. He didn't know the password for his Diagmaster account so had to wait till today. In the interim I swapped in one of the other injectors we had sitting around...instant fuel knock. Finally bit the bullet and ordered a new injector. Just finished with him a few hours ago. He had to recode the ECU for the new injector, reset soot level and regen interval, and reset pump learning time and force a new pump learn. The machine feels like brand new. Instantly way more power and runs a lot smoother. I ran it for about an hour, didn't regen once and didn't bog down near as much as it was before, so I'm guessing that it's been derated 25% this whole time. Not what I wanted to spend, but hopefully this is the end of it and the machine will last a good while. Thanks for all your input!
aint technology great?
Great wasn't exactly what I was thinking of At least it's fixed, and isn't a turd. In the back of my mind I was kinda thinking "why did I pay xx for such a piece of crap"
technology gets expensive real fast i will tell you this, kubota's ECU software is a friggin nightmare to get logged into. passwords are generated by kubota EVERY year, when the software subscription is renewed and and paid for (@ $1000 per copy) by the dealer. i dont have it on my laptop anymore... at one time we had 12 licenses from kubota for ECU software...
Yeah, the poor tech didn't have much of a good time with the software either. I spent a good hour helping him out and showing him how to do all the interval service operations. Sad when the client with a service manual has to help the dealer... Needless to say, whenever this machine is sold, it WON'T be getting replaced with a Kubota machine. I ran a brand new SSV75 over the weekend with less than 30 hours on it (sponsored dealer machine for an event we were running). Fitted with a 78" snow bucket it didn't have enough power to lift the bucket full. Same crap too, DPF and EGR on a tier 4 final machine.... :/
Sadly, that's our world now, and not likely we're going back.
I realize that. Can't beat the oldies.
Yep. Kubota over the years has made a good, solid, reliable engine. But now that engines are pretty much have to be designed using space shuttle technology, well, all brands struggle with the burden that comes with it. I recently moved to a new job, last week went out with one of the bosses to check out a used truck to use as a yard dog, and, to use as a back up truck when the brand spanking new Peterbilt tractor is in the shop. I replied "it's a new truck, it WILL be in the shop". Sure enough, that's where it currently resides, shop bay at the Pete Store.
Yep. I would agree on the solid engine, up until this new generation. Offering an engine that has zero aftermarket support, and injectors that have zero support. That to me just screams bad business.
I wager this stuff is all too new (dealing with tier 4 compliance) for aftermarket to catch up with any speed, it's a new world for that. Heck, we're all trying to wrap our heads around making engines with the workings of R2D2.
Very true. In my case, I actually phoned pretty-much all the well-known injection companies in Canada. Of the 3 or so that had a good relationship with Denso, none had any confirmed information other than NW Fuel Injection. He spoke to his rep and got the same answer I did from the main support portal. Basically the long and short of it is, Denso does not feel that there are enough products used in North America to justify creating a rebuild or exchange program for their injectors like they have in Europe or Asia. When I asked about the future plans the rep said nothing anytime soon. He also confirmed that they will not be releasing any aftermarket support. Only a factory exchange/rebuild program through authorized dealers. Yeah, this thing isn't exactly a Cummins....lol
Does anyone know of a cheaper scan tool I can buy to force a t750 into doing a regen
I have been thinking about a rental for situations like this but not needed it https://jballelectronics.com/products/diagnostic-and-tuning-tool-rental/ https://www.diesellaptops.com/pages/rental-kits If you do so, let us know how it goes.