CM2250 Regen Confusion

[Billdozer2]

Hey guys, So, I just got my Insite up and running and the first thing I wanted to check was my Aftertreatment History. It did not look good. I don't have any check engine lights and the truck has never asked me to do a parked regen. Also, my fuel mileage is fairly normal. I also do not idle the truck, unless it is zero degrees outside. All of the regens from 2-10 are all passive regens. However, the truck has been regening about every 4 hours or roughly 175 miles. Take a look.

So, I decided to do a forced regen the same way Rawze did it in his YouTube video. The final results are Regen #1 above. Now, I know in the YouTube video, the engine is a CM871 and I have a CM2250. But I'm curious why some of the numbers are so much different. Does something look wrong here? I'm looking at the Exhaust Gas Pressure, Intake Manifold Pressure, and Turbo RPM. They are much higher on my engine than the one in the YouTube video.



I took a picture of the screen every 5 mins, but the values do not change very much. So I did not include those pictures. The only time something happened was at minute 42, 50, 59, 67, and 75 the injector would turn off, the DPF intake filter temp would drop to around 550 degrees, and then the injector would turn back on again, bringing the exhaust temps back up to around 1100 degrees. Not sure if that is normal or not. Overall, the forced regen took 88 minutes. I'm not really sure why it took so long. I plan on doing an EGR/sensors cleaning/tune-up soon, but I just wanted to check out the after treatment system first so I have a before and after comparison. I'm thinking an EGR tune-up will help, but I'm curious what everyone else thinks.

For those that want to know, the truck is a 2013 Volvo 670 with 360k miles. I've had the truck since new. It was my company truck for three years until it was time to trade in. Long story short, I was unhappy with the direction my company was going with their equipment, so I decided to purchase my company Volvo last October. The DPF was cleaned when I purchased the truck at 290k miles.

[Rawze]

Did you clean or replace the Doser injector first? It could not be spraying correctly.

replaced the IMAP? Delta-P and Exh BP sensors too?

DPF Delta-P? -- Clean/replae the SCR Filter? clean out the SCR injection crosspipe?

Lots of maintenance on those CM2250's.

[szartman379]

Billdozer2, my numbers look fairly similar as well, and I did everything Rawze just said but clean the injection cross pipe. When i dropped my SCR and DPF, that pipe appeared super clean on the inside, so I didn't do anything. My forced regens take atleast 1.5-2 hours. My DPF temps go way high, sometimes 1200 degrees.

But as it was stated on my thread, my passive regens that occur in 300 miles or so seems is normal, so I guess I shouldn't complain. My first trip, roughly 1500 miles, averaged 6.5mpg. Heavy going north, light coming south, not very flat either direction.

I was getting a check engine light due to excessive regens, so the last thing i did was have the DPF and SCR cleaned. That was 1500 miles ago, passive regen 4 times

2013 pete386.

[Billdozer2]

(04-29-2016 )Rawze Wrote:  Did you clean or replace the Doser injector first? It could not be spraying correctly.

I replaced the Doser injector about 40k ago because I was replacing my thermostat at the same time. I have not cleaned the dozer since.

(04-29-2016 )Rawze Wrote:  replaced the IMAP? Delta-P and Exh BP sensors too?

DPF Delta-P? -- Clean/replae the SCR Filter? clean out the SCR injection crosspipe?

Lots of maintenance on those CM2250's.

I have not replaced/cleaned any other sensors. I plan on doing that very soon as the weather up here in NH is getting better. What is the SCR injection crosspipe? And also I was curious if I should replace the DEF dozer as well? I don't know if those are prone to failing/clogging like the DPF dozer.

[Billdozer2]

(04-29-2016 )szartman379 Wrote:  Billdozer2, my numbers look fairly similar as well, and I did everything Rawze just said but clean the injection cross pipe. When i dropped my SCR and DPF, that pipe appeared super clean on the inside, so I didn't do anything. My forced regens take atleast 1.5-2 hours. My DPF temps go way high, sometimes 1200 degrees.

After my forced regen went past an hour, I told myself I was going to shut it down at 1.5 hours because I didn't know if that was normal or not, as it was the first time the truck has ever had a forced regen performed. And I really didn't want to throw 100 gallons of diesel out the stack. My DPF temps were up into the 1200 degree area. It never goes that high driving down the road. Usually hangs around 1000 degrees.

(04-29-2016 )szartman379 Wrote:  But as it was stated on my thread, my passive regens that occur in 300 miles or so seems is normal, so I guess I shouldn't complain. My first trip, roughly 1500 miles, averaged 6.5mpg. Heavy going north, light coming south, not very flat either direction.

I was getting a check engine light due to excessive regens, so the last thing i did was have the DPF and SCR cleaned. That was 1500 miles ago, passive regen 4 times

2013 pete386.

I remember Rawze saying "about every 300 miles or so" was normal. That's why I was starting to get concerned when my truck was regenning every 175 miles or so. Never had a check engine light for it. But figured it was hurting my fuel economy, so, I should probably do something about it.

[Unilevers]

passive regens take 1hr max - if it is going longer something is wrong. the injector should not turn off and on and the temps should rise and hold fairly steady then fall for the cooldown.

in the aft. history pic your dpf is plugged - the numbers are too high and too close together. it also only came down to 2.2 after a full regen which is still marginal. a properly functioning system will regen every 8-12 hrs of operation - 175 miles between is crazy and that truck will very soon get stuck in the dreaded "constant regen" cycle

cm2250's run smaller turbos than 871's so the turbo speed is higher, the vgt position is higher, and the exhaust pressure is higher - that is normal.

[snailexpress]

All you guys with 2250 / 2350 can donwload DESA from Cummins email them for password and use this test to figure out what is wrong.
My regens are good in time and temperature but

[Billdozer2]

(04-29-2016 )Unilevers Wrote:  passive regens take 1hr max - if it is going longer something is wrong. the injector should not turn off and on and the temps should rise and hold fairly steady then fall for the cool down.

All of my passive regens have taken less than an hour. I think one took close to an hour, but figured it was because I was rolling though some hills and the exhaust never got hot enough. I was really confused when the injector would turn on, the DPF intake temp would drop to 550 or so, DPF output temp would come down but slowly and only to 750 or so, and then the injector would turn back on raising both the input and output back to 1100. Now I know that is not normal. Great.....

(04-29-2016 )Unilevers Wrote:  in the aft. history pic your dpf is plugged - the numbers are too high and too close together. it also only came down to 2.2 after a full regen which is still marginal. a properly functioning system will regen every 8-12 hrs of operation - 175 miles between is crazy and that truck will very soon get stuck in the dreaded "constant regen" cycle

Well, I did my normal run today and after performing that forced regen last night, the truck did not regen until about 250 miles of driving. Which is better (Yay!) But still looks like it is not good enough. (Boo.)

Do you think performing an EGR/sensor cleaning/replacing will help? Or should I pull the DPF and get it cleaned? I'm kinda bummed cause it was just cleaned 70k miles ago. Although I did not see the end result other than a Repair Order that said the back pressure was around 1.2 if I remember correctly.

(04-29-2016 )Unilevers Wrote:  cm2250's run smaller turbos than 871's so the turbo speed is higher, the vgt position is higher, and the exhaust pressure is higher - that is normal.

Thanks for the info! What about the Intake Manifold Pressure? In the youtube video it was around 10inHg during the regen. But mine is up in the mid 30's while regenning. Just a CM2250 thing as well?

[Billdozer2]

(04-29-2016 )snailexpress Wrote:  All you guys with 2250 / 2350 can donwload DESA from Cummins email them for password and use this test to figure out what is wrong.
My regens are good in time and temperature but

Seems like that would be a really useful tool! Is the password free from Cummins?