CM 871 Code 2639, DPF won't clean

[Doops22]

I've got a CM871 ISX and the driver hit the regen switch to "stop", so it has been skipping regens. It got plugged up and derated, and he limped it back to the shop. I've been doing stationary regens and now have code 2639 active for DPF plugged and the dpf light is on solid, so quickserve tells me this means it is at level one (lowest level plugged) and the only action needed is a stationary regen. I've done 5 stationary regens and this code still won't clear. The only other code I am getting is 2215 for low fuel pressure. The only symptom i've noticed with that is hard starts. Could that affect the regen at all? Should I just keep doing stationary regens until it clears or try something else? I have a Cummins Quickcheck code reader but no insite to see data.

[Rawze]

maybe pull the DOC and DPF and have them both baked and de-ashed.

Chck DPF Delta-P sensor, clean Doser injector tip, and do an EGR tune-up.

[Doops22]

I started on the egr tuneup and noticed traces of antifreeze in the egr tube/intake pipe so it looks like I’ll be doing an egr cooler. I also noticed inside the head around the intake valves are wet. This one is worse than the rest. Normal or do I have injector oissues too?

[Rawze]

(03-06-2019 )Doops22 Wrote:  I started on the egr tuneup and noticed traces of antifreeze in the egr tube/intake pipe so it looks like I’ll be doing an egr cooler. I also noticed inside the head around the intake valves are wet. This one is worse than the rest. Normal or do I have injector oissues too?

make sure the "wetness" is coolant and not condensation. ISX is notorious for getting condensation in egr and intake circuits.

Test EGR cooler by pressurizing the coolant system over night to 20-psi and looking for coolant buildup in it next morning instead of jumping to conclusions.

-- yeah, its common for valves to be slightly wet with oil on older engine/head. If it gets bad enough, it will cause DPF clogging (or smoking issues for trucks that have been de-mandated).

[Doops22]

I had red droplets in the EGR tube where it meets the intake pipe so I am assuming it is antifreeze and not condensation but I will pull the outlet of the cooler apart and check there too. Thanks for the help.

[Doops22]

I did the test found on quickserve using fleet guard coolant test strips mixed with soot from the egr cooler outlet, it is supposed to change color if there is coolant in the soot . I have a baseline of distilled water, 2 samples of soot mixed with 25ml distilled water, and then a sample of the coolant that was taken from the system. Judging by this test I’d say it’s not leaking. Trying to find an adaptor to hook my pressure tester to it next.

[Doops22]

So I pressure tested the coolant system and no coolant or wetness at the egr outlet so I put it back together. I had the DPF and DOC cleaned and baked. Completed the egr tuneup with a new egr delta P sensor. Still have code 2639 active and the DPF light on the dash. I took it for a drive and the light went out for a mile or 2 but came back on. I found in my code scanner where I can see DPF delta P and it shows Peak Soot Filter Delta P 0.74 PSI. The filters were cleaned and baked so I know it isn’t plugged, any other ideas to clear this code and light?!

[Unilevers]

.74 psi is pretty high for a new filter....

[Doops22]

The filters were cleaned and baked. Is that high enough to trip the light? Maybe the DPF delta P sensor is bad?