335 with an ISC CM2150

[hookliftpete]

Hi folks,

I'm a new O/O of a pete 335 with an isc, as subject line notes. I'm running roll off dumpsters with it, which is mostly local miles, short runs on the highway. I've got experience in the dumpster business, just not in the truck repair aspect.

In looking for help with the regen/dpf issues, I happened across this forum. To the best of my abilities, I have followed some of the things suggested here for maintenance of the aftertreatment system. My knowledge of engines is basic, but I'm quite happy to tear stuff apart and fix it. I'm just not in the position to have much down time, so I am trying to be careful in what I'm doing.

Truck was purchased in March of this year, and has been in the shop twice for the dpf/doc being clogged. First time it derated and was towed back to the pete dealer. They cleaned both dpf/doc and forced a regen. It ran about 4 months afterward, it asked for a parked regen, and would not complete it. I took it to cummins, they did the same, as well as a snap test, found a 'haze' at 50% throttle, and did a once over on the engine. They suggested that the injectors 'might' need replaced, but no definite answer.

Since then, it soon returned to a 4 hour interval of active regens. I try to get highway time to run the process out, but it makes no difference.

Because I can't spend another 2k for cummins/pete to clean the filter/doc and call it good, I pulled the dpf and doc and hosed them out gently. The dpf ran clean very quickly, the doc by my eye, was about 30-40% face clogged. Coolant levels appear to be stable.

I let both filter and doc sit in front of a fan overnight, then reinstalled them and allowed the truck to warm up naturally, until I saw no steam from the stack. Took about an hour.

There was about 4 days of no active regens, then back to the 4 hour regen interval.

Since then, I've pulled a number of sensors and scrubbed the soot off of them, pulled the tube from the egr cooler to the egr valve and cleaned it, been keeping an eye on coolant, doesn't appear to be using any, and the soot levels that I encountered in the little bit of cleaning seemed quite normal.

The engine has about 84k miles on it and about 3500 hours, getting about 6.25 mpg, all around average.

I'm a bit hesitant to tear too much more apart, whatever help can be tossed my way will be very much appreciated. Thanks!