CAT 277d DPF code

[Tall.Timber]

Hello,

Been doing some research but not a ton of information on this issue. I have a 2015 277d with 1100 hours that has thrown a 523602-0 (Regeneration Frequency) code twice in the past 30 hours. Turbo was replaced 30 hours ago. The second time CAT came out to reset this they preformed a compression test and found 300psi on all cylinders. I am torn on where to start. Should i be throwing money at the motor or the emissions first? I am tempted to get a copy of the ET software i see advertised and run the machine hard and clear the code if it comes up again. I have a gut feeling that it is just a clogged DPF from its easy life. Machine appears to burn no oil, and running with the oil cap off shows no signs of blow by. Thoughts?

 

[Mobiltech]

I would be concerned about the 300 psi compression if the test was done right .
300 will barely fire a Diesel engine which also means tons of smoke which leads to a plugged dpf in a hurry.
Can you take the exhaust off at the turbo outlet , start it and see if it’s smoking bad when cold.

 

[Tall.Timber]

So i did as you mentioned and took apart the turbo outlet. Two of the studs on the DPF were not coming out so before i messed anything up i elected to remove the DPF mounting bolts to allow me to rotate the DPF enough to create a gap for exhaust to come out. First cold start the pipe fell back in and sent anything that would have been present into the DPF. Although initial start showed no smoke and nothing from the remaining gaps of the unbolted pipe. Second cold start(About 5-7 minutes after) the gap stayed and zero smoke was seen. I also scoped the DPF and it seems pretty clean. Although CAT did preform a parked regen last time they were out. I took some videos and pictures and made a short youtube video of it.

Machine has been starting and operating as if there is no issue. I am wondering if i should preform my own compression test to validate? Seems odd that a "hurt" motor would see 300-320 psi across all cylinders. i would expect one to be an outlier.

 

[Mobiltech]

From that video I wouldn’t be too concerned about anything in the engine. There should be some grey smoke if it’s low on compression. Sounds good and looks fine.
It may be that you’re just not working it hard enough to clean out the soot in the dpf.

 

[ozarkag]

We've had some luck removing and physically cleaning the dpf after an event such as turbo failure. Using hot water pressure washer with the tip removed. So basically just rinsing, no pressure.
With no codes except regen frequency it may very well work to reset several times and try to run it hard and burn it out.

 

[Tall.Timber]

From that video I wouldn’t be too concerned about anything in the engine. There should be some grey smoke if it’s low on compression. Sounds good and looks fine.
It may be that you’re just not working it hard enough to clean out the soot in the dpf.

Could be, I have a diagnostic adapter and software coming this week. I am going to get that functional so i can clear the code if it presents its self and run the machine hard this weekend. After the investigation today i think i am straying away from needing a motor. This seems like it may be a DPF cleaning/replacement worst case.

 

[Nige]

try to run it hard and burn it out.

That's what these engines need. Being run at low load or worse still idling for extended periods is not good for them.

 

[92U 3406]

Check the delta p sensor and the hoses going to it. Might need ET to see what its reading.

 

[Tall.Timber]

Check the delta p sensor and the hoses going to it. Might need ET to see what its reading.

I have ET coming this week. I assume i will want to check this with the machine running? Or will a product status report contain this information?

 

[92U 3406]

I have ET coming this week. I assume i will want to check this with the machine running? Or will a product status report contain this information?

Sometimes the tubes coke up and give goofy readings.

Probably not a bad idea to run a datalog and see what that sensor is reading.

 

[Tall.Timber]

Got my CAT ET setup today and ran a Product Status Report and grabbed a couple of the DPF status screens with the machine not running as i have the exhaust still taken apart. I did start again from dead cold and again had zero smoke. I think compression issues are out of the question. Any thoughts on these tables? Nothing seems too off to me. Aside from the "desired engine intake throttle actuator position" being 93%. Soot load at 21% seems reasonable.

To confirm CAT completed a parked regen and the machine has ran for approximately 30 minutes since then.

 

[Tall.Timber]

Got the machine out today and ran it hard for an hour, no issues at all. shut down for about 6 hours then went out to do a quick data log. Data log from the run is attached. 5 minutes long first 2:30 is at idle. Remainder is at 2000 RPM. I also have two photos one is from a cold start. and the second with differential pressure 0.6psi is at 2000 rpm. Nothing seems too off to me. Thoughts? Going to go back out tomorrow and run it hard again.

EDIT: appears i cannot upload the SDF datalog file. I will get screenshots from ET if anyone can point me in the direction of what would be useful to see.

 

[Tall.Timber]

Got out and ran the machine today. Ran hard for around 3 hours(2000 rpm digging dirt) then got the code once i was about done with that work. Ran a regen which completed successfully then reset the DPF time interval in ET to clear the active code. Ran again for about 20 minutes before throwing the code. again ran a regen and reset the interval. Then ran a data log to capture the code. Code did not throw in about 45 minutes of running. I did catch one regen on the datalog. I have two graphs attached. One is the Differential pressure and time when the regen is called for. Looks like the differential pressure was about 1.15psi when the regen happened. The other is the Soot mass #1 when the regen happened and it looks like there was a spike to 26g. Not sure if either of these are a trigger for the regen. I dont have a good way to show it but i did find a couple of odd things while watching the data during the regens.
1.) Soot Mass #1 never gets much below 20g at any time. even immediately after a regen.
2.)DPF soot percentage drops to almost zero during the regen but when the regen is complete the value jumps right back to 22-23%

Is there a sensor that is reading soot mass? or is that done with the differential pressure?

Thoughts?

 

[Nige]

You need one of the Tier 4 emissions specilists to chime in here.

 

[Chrisso]

Soot Mass #1 never gets much below 20g at any time. even immediately after a regen

That's the problem.

I have a gut feeling that it is just a clogged DPF from its easy life.

I reckon the failed turbo had something to do with it. How did it fail?

If you can't fault the differential pressure sensor I'd say your DPF is due for a clean. There's places out there that do this fairly cheap, but it's usually engine out.

Is there a sensor that is reading soot mass?

I don't think you'll get a definitive explanation from anyone. It's probably done via software strategy based on a combination of sensor readings.

As 92U mentioned above, if the differential pressure (delta P) sensor tubes aren't clogged, and wiggling the wires on this sensor doesn't change the readings in ET, chances are it's probably fine.

 

[ozarkag]

How bought lying to the ecm and saying the dpf has been cleaned. Soot load reset in the software. If it actually needs cleaning will regen on differential pressure.

 

[92U 3406]

The issue there is I believe the ECM calculates the ash loading over the DPF's life as part of the regen strategy. If you tell it that its clean then it no longer accounts for the amount of ash that has already accumulated in the DPF.

If the turbo had failed and put oil into the DPF then that may be your root cause. I could never find a shop anywhere that would even attempt to clean a DOC or DPF that was contaminated with oil. Replacement with new or reman were the only options.

To pull and replace the DOC and DPF count on it being a 12 to 14 hour job. The imagineers designed these machines thinking they'll never have issues.

 

[Chrisso]

That's a good point. Oil can melt the DOC and DPF internals.

Also that's why it's important to tell the ECM when the DPF has been cleaned/replaced. It's in there under Service Procedures in ET if I remember correctly.

 

[Nige]

How bought lying to the ecm and saying the dpf has been cleaned. Soot load reset in the software. If it actually needs cleaning will regen on differential pressure.

Not smart from what I know. Can cause the matrix in the DPF to literally fall apart. Correctly cleaning a DPF is a damn sight cheaper than a new replacement......

 

[Tall.Timber]

I reckon the failed turbo had something to do with it. How did it fail?

I am not entirely sure, turbo failed and was replaced prior to my ownership. I can only assume it put oil to the DPF.

Did a little more digging today. Took out the Delta P sensor and hooked a longer hose to the pipes. Blew into them by mouth to feel for any obstruction(I dont think this procedure is cat approved). Exhaust side felt no resistance. Inlet/turbo side felt maybe a slight resistance followed by a small "pop" and then no resistance. Not sure if this was in my head or a real dislodging of material. put it back together, hooked up the computer and ran the machine. delta P and soot mass #1 was slightly better at 0.4-0.6psi(idle-2000RPM). And soot mass#1 read a max of 18g( still high but better than it was). I also found the pictured sensor unplugged. I assume that is an air intake temperature sensor and likely doesn't have much impact on this issue as there are no related codes.

After reading the above i think i am going to force parked regen and see what happens after finding that delta p possibly clogged. If i fall into the same data as before I am going to pull the DPF and see if i can get it cleaned. If cleaning is successful i will plan to reset the soot levels. I think that is my best approach at this time.