2016 isx15 2350 x100 cummins

[catnred]

smoke bellows out the stack while going through a def regen while shifting up through the gears!!
has done this maybe about a dozen times in 300k miles.
noticed ONLY when going slow enough to know there was a regen in process and couldn't go over say 40 mph while shifting once on the highway Clears up!!
any ideas why?

[Waterloo]

How many miles on the truck? When was the last time the cans were removed and baked, flow tested, etc? Has the SCR system been serviced? Filter cleaned? Regen history? Do you have Insite? Have you completed an EGR Tuneup? You do know about the fuel pump?

[tree98]

You probably have a cracked dpf along with 10 other problems that will soon be revealed.

[catnred]

Thanks for the response.
the mileage is 400k it has been doing this for about 2 years.
I don't have insite,scr was just serviced doser was 70 % plugged cleaned it,filter changed,
soot load normal,intake temps,550 & 890 outlet temp.1195,differential pressure 1
cans removed and baked at 200k,egr cleaned
fuel pump updated

[Chamberpains]

(11-12-2019 )catnred Wrote:  I don't have insite

How does it feel to be willingly blind for 2 years? All you had to do is not wear horse blinders and buy the glasses to see.

Go get a computer and Insite and carry it with you every trip.

[tree98]

You absolutely do need insite,it's as important as fuel in your truck.

[hhow55]

Mine did this exactly as you describe. Turned out to be my fuel system was infected with algae. Started treating with killem, and it eventually went away. I used the entire bottle as directed. I also started using a 10 micron filter in the davco.

[Rawze]

In cooler weather, sometimes a truck will build up a bunch of fuel in the DPF because it is not hot enough to ignite, then suddenly it will burn off all at once when you start climbing a hill. - Makes some huge white smoke that is so thick sometimes that you can't even see your own trailer behind you... Nothing wrong with the system, everything working fine, regen numbers ok too.

-- gotta love these "Environmentally Friendly" that dump and waste fuel into the tail pipe -- ehemm...; trucks eh?

[catnred]

(11-13-2019 )Rawze Wrote:  In cooler weather, sometimes a truck will build up a bunch of fuel in the DPF because it is not hot enough to ignite, then suddenly it will burn off all at once when you start climbing a hill. - Makes some huge white smoke that is so thick sometimes that you can't even see your own trailer behind you... Nothing wrong with the system, everything working fine, regen numbers ok too.

-- gotta love these "Environmentally Friendly" that dump and waste fuel into the tail pipe -- ehemm...; trucks eh?

Thanks Rawze I think your right on and I thank you for your service.
I guess its obvious how old school I am! [70 years old]
Last cummins I drove was A shinny 290 in a 1973 road commode!!
Rawze this website is worth its weight in gold!!!
I among many owned CATS from the 425 to the MBN to the Ascert These trucks got old and we got old!! I myself traded in a 2007 w900l kw on this 2016 Peterbilt 579 with lots of warranty and 7 miles per gallon isx cummins good running engine even with the DPF just trying to decide when to ------ it!!
I don't have insite but I have mechanics all who have insite!!
we keep it clean or try to! replace anything that needs replacing we just couldn't figure out why on rare occasions I was blowing out smoke.
I pick up loads of zip boards in a warehouse that's kept at 80 to 90 degrees in northern Maine there is quite a difference in temperature out side.
And this past week I sat in traffic a couple of hours it went from 34 degrees to 28 degrees in 2 hours the smoke bellowed out until I got up to speed.
Thanks to everyone hope to learn more before I give up and retire.