Excessive Regen (non stop)

[BrandonOlsen]

2018 579 Peterbilt Had engine light come on monday morning while it was idling to warm up for the day. Truck since then would regen anytime I come to a stop sign or anything to do with slowing down where rpm got under 1000. Engine light went away around 11am and turned back on shortly until 4:30pm and shut back off. Took truck in and had fault code 3725. They replaced inlet nox sensor. Went to pick up the truck and when I turned the key the ignition was just clicking and the bunk alarm and espar heater was turning on and off. When the key was turned there was no power to the truck at all. Hooked up battery cables and did nothing. Mechanic did something with the battery cables and got it started. I noticed today that when I left the shop and was coming to a stop sign it started to regen. Here’s the kicker. I pull into the farm as it starts to regen because I’m slowing down and got parked, if I idle it up to 1000 and then cut the cruise it will stop the regen. If I idle it up a notch to 800 it starts to regen. Idle back up to 1000 and cut the cruise it stops the regen. So truck normally idles at 700. If I bump it up to 800 it starts a regen and can stop it by putting it up to 1000. Whenever I do idle I’ve always idled at 900-1000 and never had this issue. It sounds like where the egr cooler is it makes some sort of leaking noise and told that to the shop and they said they couldn’t find a leak there and what I’m hearing it the exhaust going through egr valve when it opens. But it seems I can hear it at all times. And while it regens it sounds more like a ticking noise. I don’t have access to insite so I’m very limited to what I can see. I have geotab to track ifta and that will show engine codes but not really live data other than a few things ( Temps and fuel consumption ) anyone here anything like this ?

[Rawze]

first of all.. if the 'regen required' light is coming on then the system is already in dire straights.. and the engine is the issue. It is Not the DPF system, as it only catches the soot.. it does not make it. You are not going to cure it much by doing a parked regen. A parked or forced regen does not "clean it out completely" and is only going to only clean it by about 2% at best. Parked and forced regens are nothing but a band-aide that only allow you a few hundred more miles once it starts asking for them regularly. The system is done-for and needs some serious servicing at that point.


What need to happen at this point is that the DPF and DOC both need to be removed, pictures taken of their faces, and then taken to a stealers$it to have them baked, de-ashed, then flow tested. Once that is done, and they are put back on, then in Insite, a 'Maintenence reset' and 'DPF Replacement' procedures need to be done to let the ecm know that they were cleaned out.

NEXT would be to FIX THE ENGINE ISSUES that caused the situation to begin with. Doing a thorough EGR tune-up, replacing the egr and intake sensorsthat are more than a couple years old like the IMAP, Delta-P, etc.. and cleaning out all the egr piping.
ref: http://rawze.com/forums/showthread.php?t...122#pid122

... AND fixing the turbo leaks and CAC leaks that the engine, intake, and exhaust may have.

Only after that will the emissions systems become somewhat reliable again. There are no band-aide shortcuts to making the engine healthy again.. it only leads to more headaches and chasing your tail endlessly... and no shop is going to do any of this stuffs for you.. the simply either don;t care.. or are too damn dumb to service the engine properly, only chasing the more expensive components instead.

last but not least... if the fuel pump has more than 400k miles of run time on it (or 8,000 hours).. then it needs all new guts to prevent catastrophic engine damage.. and as well.. you need to do a rail leak-down test to ensure you don't have any fuel rail issues or leaky injectors.
ref: http://rawze.com/forums/showthread.php?t...2#pid69262

[BrandonOlsen]

(11-19-2022 )Rawze Wrote:  first of all.. if the 'regen required' light is coming on then the system is already in dire straights.. and the engine is the issue. It is Not the DPF system, as it only catches the soot.. it does not make it. You are not going to cure it much by doing a parked regen. A parked or forced regen does not "clean it out completely" and is only going to only clean it by about 2% at best. Parked and forced regens are nothing but a band-aide that only allow you a few hundred more miles once it starts asking for them regularly. The system is done-for and needs some serious servicing at that point.


What need to happen at this point is that the DPF and DOC both need to be removed, pictures taken of their faces, and then taken to a stealers$it to have them baked, de-ashed, then flow tested. Once that is done, and they are put back on, then in Insite, a 'Maintenence reset' and 'DPF Replacement' procedures need to be done to let the ecm know that they were cleaned out.

NEXT would be to FIX THE ENGINE ISSUES that caused the situation to begin with. Doing a thorough EGR tune-up, replacing the egr and intake sensorsthat are more than a couple years old like the IMAP, Delta-P, etc.. and cleaning out all the egr piping.
ref: http://rawze.com/forums/showthread.php?t...122#pid122

... AND fixing the turbo leaks and CAC leaks that the engine, intake, and exhaust may have.

Only after that will the emissions systems become somewhat reliable again. There are no band-aide shortcuts to making the engine healthy again.. it only leads to more headaches and chasing your tail endlessly... and no shop is going to do any of this stuffs for you.. the simply either don;t care.. or are too damn dumb to service the engine properly, only chasing the more expensive components instead.

last but not least... if the fuel pump has more than 400k miles of run time on it (or 8,000 hours).. then it needs all new guts to prevent catastrophic engine damage.. and as well.. you need to do a rail leak-down test to ensure you don't have any fuel rail issues or leaky injectors.
ref: http://rawze.com/forums/showthread.php?t...2#pid69262

Thanks for the response rawze. The regen required light does not come on. Nor have I had to do a forced regen. Whenever it has ever done a regen it’s always when I’ve been driving and you could only tell it was doing a regen is when you came up to a stop sign and got under 1000 rpm and the hot exhaust light came on and you could smell it. It’s doing the same thing as that where it seems like it’s a regen but the hot exhaust light isn’t coming on and the smell isn’t there ( atleast I don’t think ) I have a bad nose from COVID so smelling things are hard. Truck has 660,000 miles . Was overhauled at 600,000 fuel pump was replaced at that time of over haul

[BrandonOlsen]

Forgot to mention. When it was overhauled all new emissions was done at the same time

[Rawze]

the last part of my post still applies.. make sure it will pass a rail leak-down test, exactly like i show in my video ... if it will not then you are wasting your time trying to solve any other issues.

[MCRENT]

You have to get Cummins insite.. you are pissing against the wind without it.. not sure which version you have to get with the 2018 year engine or truck but that is the 1st thing you need to do. Or take it to one of the recommended mechanics on this forum. In my experience if you doing a constant regen you have leaking injector or loose quill tubes or a possible electrical issue tricking the computer into thinking you need a regen. At 600 K it s a good idea to just change all the sensors on the engine if they have not been done lately just to make sure they are not sending bad info to the computer..

[BrandonOlsen]

(11-21-2022 )MCRENT Wrote:  You have to get Cummins insite.. you are pissing against the wind without it.. not sure which version you have to get with the 2018 year engine or truck but that is the 1st thing you need to do. Or take it to one of the recommended mechanics on this forum. In my experience if you doing a constant regen you have leaking injector or loose quill tubes or a possible electrical issue tricking the computer into thinking you need a regen. At 600 K it s a good idea to just change all the sensors on the engine if they have not been done lately just to make sure they are not sending bad info to the computer..

All of the sensors have been replaced right at 60k miles ago. I’m thinking that it’s more exhaust pressure than a regen. Just got insite today haven’t been able to mess with it yet