passive regen

[vinny933]

2019 granite , i have another post here where i found exhaust gasket leaking which seemed to help keep soot level in check . i took the truck to mack they said 7th injector was partially clogged and replaced it. so while there i had dpf filter cleaned 2 weeks later truck asked for a parked regen is this normal. mack says its fine as long as it completes regen. i had this truck since new 3 years never ask for a parked regen until this year. motor is still under warranty i want it fixed if there is something wrong   egr / turbo/ injectors. what to look for or tell mack to look at

     

[Onyx610]

Did you get the truck fixed?

[fjh]

On 1/16/2023 at 2:50 PM, Onyx610 said:

Anytime you replace a part you should. The 7th injector is high on the list like a turbo. 

See how it goes Time will tell on this one!

[Mackpro]

If the ports are getting clogged on the Venturi pipe where the EGR differential pressure sits it tell the engine ECM that the EGR flow is below the target flow rate. Even though the actual flow rate probably within specs , the engine ECM will command the EGR valve to open more to meet the target flow rate . So now you got more than needed EGR flow( dirty exhaust) going back through the engine. This produces more than usual soot to clog the DPF filter. I have had this happen on the MP8 even with the newest EGR diff sensor/Venturi pipe set up. Below is a picture of the newest sensor/ pipe for the MP8. I usually pull them off and clean them on the inside. 

[Onyx610]

It’s also not a step lol

[fjh]

13 minutes ago, Mackpro said:

If the ports are getting clogged on the Venturi pipe where the EGR differential pressure sits it tell the engine ECM that the EGR flow is below the target flow rate. Even though the actual flow rate probably within specs , the engine ECM will command the EGR valve to open more to meet the target flow rate . So now you got more than needed EGR flow( dirty exhaust) going back through the engine. This produces more than usual soot to clog the DPF filter. I have had this happen on the MP8 even with the newest EGR diff sensor/Venturi pipe set up. Below is a picture of the newest sensor/ pipe for the MP8. I usually pull them off and clean them on the inside. 

YUP ! Start at the beginning!  Right Pro !?

[mdixon]

After dpf cleaning, if the truck wasnt run through a service reset and stationary regen, would it be possible it's just not calibrated to recognize a clean dpf? @Mackpro maybe cause it to go to the point of needing a stationary to re calibrate what "full" is?

[Joey Mack]

would a 'learn data re-set' be the answer?? 

[mdixon]

Generally for me if things happen to a component immediately after a service of THAT component, I assume that a procedural step or action was overlooked. There's lots of those when your dealing with emissions stuff.

[mdixon]

Just now, Joey Mack said:

would a 'learn data re-set' be the answer?? 

If it wasn't followed by a stationary regen and a conversion test it wouldn't have the necessary data to calibrate fully

[Onyx610]

Have to reset soot level 

[mdixon]

When a stationary regen is "complete" the ecm measures the dp value and stores it for later, to find a mean value it can use to make decisions later. 

[Joey Mack]

I thought I used to re-set soot level and do a learn data re-set, then a forced re-gen. .. Back when I worked on these at Mack..  I need to just watch , instead... 🤫

[mdixon]

Sry cummins emissions does conversion tests.

 

After dpf cleaning, reset soot, reset data, stationary regen

[Joey Mack]

my bad.... Thought it was an MP.. 

[mdixon]

nope, I got confused. Your right. 

Although to be fair.... it's never actually stated

[Mackpro]

I just deleted a post here as I was forgetting which truck I was referring to . I talked to some guys today at the dealership. They are having a rash of EGR coolers cracking and or clogging on the 2019 to 2021  MP8 trucks . Both in the GR and Anthem trucks . 4 in the last month or so. I wonder if this could a issue. I can’t remember if you posted if the engine software was up to date. 

[Mackpro]

On the common rail engines there are 3 types of regens ( possibly 4) that you can do using Tech Tool . A Soot regen and a Sulfur regen  and a Crystal  Sublimation regen. I’ll see if I can find out if possibly one of the others need to be done instead of the regular soot regen . 

[Vmac3]

I also had bad injectors cause this same issue. Also, if there is too much particulate matter in the exhaust this will soot load the egr and aftertreatment system as well. Maybe check the basics since its pretty simple to do (CAC, intake system for leakage and a cylinder contribution test). 

V

[mdixon]

10 hours ago, Mackpro said:

On the common rail engines there are 3 types of regens ( possibly 4) that you can do using Tech Tool . A Soot regen and a Sulfur regen  and a Crystal  Sublimation regen. I’ll see if I can find out if possibly one of the others need to be done instead of the regular soot regen . 

I know with cummins aftertreat systems (onebox) if any SCR components are changed/cleaned, a nox conversion test has to be run 5 minutes after a stationary regen to calibrate the dosing module to 0 nox. This gives the computer a baseline to compare and make adjustments against as stuff wears, and to prove mechanical function before it'll deactive codes.

 

Maybe something similar is needed here with the dpf cleaning?

[vinny933]

i gave up on this for a while went on vacation after changing a few more sensors because nothing seemed to make a difference. had the thought to call  mack one call to see if there where any updates and guess what there was ,  an ecm update and a aftertreatmeat control update after downloading them truck seems back to normal , i get these free until 2024 was wondering why nobody ever called or said anything at the dealer . thanks for everyones help 

[fjh]

58 minutes ago, vinny933 said:

i gave up on this for a while went on vacation after changing a few more sensors because nothing seemed to make a difference. had the thought to call  mack one call to see if there where any updates and guess what there was ,  an ecm update and a aftertreatmeat control update after downloading them truck seems back to normal , i get these free until 2024 was wondering why nobody ever called or said anything at the dealer . thanks for everyones help 

Thanx for the update hopefully this helps others in the same situation ! It does pay to have the truck ecms updated from time to time and for what its worth other than checking for exhaust leaks and obvious stuff first a guy should do up dates before doing any in depth digging into cleaning of venturies and  Parts chucking etc.