Active Jake acts like regen lowers soot and pressure

[dhafuje]

{original e-mail message/question repaired by Rawze. Some of it has gotten lost.} ...

I am a truck o/o, I watch your videos on YouTube and read the forum, but I would like join the forum to post my issues with
Cummins six 15, actually I need your advice what to do. I am having issues with isx15 regen problem.

I saw someone post same issue that I have but there was no answer to how he solved the problem.

Truck info 2015 KW T680 with 2350 Cummins isx15

New DOC, New DPF,1 month old new/ Reman turbo from Cummins and new turbo actuator,

Cleaned egr valve all sensors of egr new 3 months old, cleaned cross pipe as you advised.

new differential pressure sensor and temp sensor for dpf, new valve seals, injection checked all look good I replaced one injector that failed,

When I did a month ago the valve seals, they replaced all injectors connectors plus one injector
Then cleaned dpf and doc, I did snap test no smoke. Cleaned and checked dpf pressure sensor tubes no restrictions.
O yeah new after treatment injector and new DEF injector. 4 months and 1.5 months old.

After the turbo replaced for no reason because Cummins said it, they suspected the turbo rpm was too high in about 71.000 rpm, but the new one does the same 61000 to 104.000 rpm depending what is going on at that moment.

There is one thing I noticed with insite connected to while driving, when the turbo boosts the dpf pressure sensor goes up up to 2.9 inHg
Then it shows soot going up on the dpf when it gets between 2.9 to 3.5 oz soot then the dpf starts automatic active regen while driving, first doc and dpf get hot but spraying.
The soot build up can get 2.9 to 3 oz within 2 hours depending if I have wind against me or constant claiming hills in the west,

Another’s strange thing I noticed when the jake break comes on the soot build up goes down within minutes better than the regen can do, 3 0z of soot goes to 0 oz let’s say 10 minutes down hill jake break active _. $35000 parts and labor in 1 year, last week Kenworth said bring in the tests fuel systems $650 diagnostic snap test again checked dpf and doc restriction test dpf, they said we cannot find anything run until fault comes on and this this is doing active regen every two hours or 4 hours depending I f am on the hills or hard wind against me with turbo boosting the harder the boost the quicker the pressure builds up, last week in Wyoming hills I had fault code 2754 1 time I cleared then changed dpf pressure sensor, after driving couple hours it came on one more time then I cleared again it didn’t come back. But the regen problem is still here

Biggest mystery jake break taking the pressure and the soot down?

[dhafuje]

Any ideas why is this happening? And what is the solution, I have suspicion that the new turbo is no good but without codes, Cummins do not want to accept its bad turbo but I could be wrong too

[Rawze]

(05-28-2021 )dhafuje Wrote:  ...
After the turbo replaced for no reason because Cummins said it, they suspected the turbo rpm was
...

$35000 parts and labor in 1 year, last week Kenworth said bring in the tests fuel systems $650 diagnostic snap test again checked dpf and doc restriction test dpf, they said we cannot find anything
...

Well, first and foremost... you went to the stealers$its to have that type of work done. They are going to rape you over and over until their expensive guessing finally fixes it .. or you will go broke paying them endlessly to throw the most expensive parts at that they can come up with.. those OEM repair shops are only trained to sell you parts and not solve anything properly. - THAT is why you spent $35,000+ and got nowhere with it so far. Your letting them get you for all that you are worth. <- that seems to be problem #1.

=====================

As far as your problem goes... start by posting a pic or 2 of the regen history. That will let everyone on here know what it is doing overall.

You also did not mention how many hours/miles is on this engine, etc. that may help too. ALso when was the last time the software was updated?

What is the engine ser#, and what software is Insite reporting is installed into the engine?

- Those would be good places to start so that others can see more of what is going on.

Also, when did this problem start?

- Has anyone replaced the exhaust back-pressure sensor?... and verified the circuit for it was clear?.. The small pipe that feeds it and the channel for it through the thermostat likes to plug up, make it have bad readings... a all while never throwing a fault.

- Lastly,.... if it has been a month or 2, and is throwing faults all over again for excessive pressures... pull the DPF/DOC and take pictures of their faces. Have then baked, de-ashed, and flow-tested again... make sure they are still good. Post pics of the faces on here for some opinions ... See how clogged up they really are. - It is a filter, it does not make soot or get face plugged that quickly without the engine causing it. Find out what the DPF is getting plugged up with and is complaining about.

- Also.. are these after-market units? or are they reman? or are they OEM?

Also, how old is the SCR element? and has anyone inspected its face? to see if it is starting to plug up?


* Has anyone bothered to pressurize the whole engine (front and back of turbo plated off) to 30-psi and looked for boost, exhaust, and EGR leaks? .. I am betting they have not.

* Will it pass a rail leak.down test?.... if so, then what is the leak rate after 1 minute?



just some thoughts that come to mind so far.

If you don't start grabbing a wrench and taking your problems into your own hands then that stealers$it is going to run you out of business... because they are not trained to solve the problems.. they are trained to follow software that is about 30% accurate on its best day, they blindly do what it sais to do, and replace expensive parts until it magically goes away.

- Personally, I cannot imagine giving someone $35,000 of my hard earned $$$ for issues like that, and having no long term solution. That kind of wasted expense in trucking these days vs. knuckling down and figuring out how to solve at least the medium problems on your own is exactly why a lot of O/O's go out of business. I am guessing that you are learning this the hard way.

[dhafuje]

The dpf and doc was last expected and cleaned 3 weeks ago, the engine has 685.000 Miles
Serial number is 79750237,

All the parts are oem DPF and the DOC are Cummins reman, same thing for the new turbo it’s also Cummins reman, the dealer updated the software in April 2021 When they installed the new Turbo,

My problem started April I had code 2754 I went to first dealer they said the problem is not the sensor it’s turbo claiming turbo is pushing too much boost 71000 RPM, I said ok 12000 Bill later and 2 days I was out with new turbo, 1.5 hours later the truck started doing passive regen non stop, then I called them I told them what is happening, they asked me if I have engine light or mill light I said no, later light came one saying one turbo injector failed, I went to next dealer replaced that injector and the connector, then the regeneration went on nonstop mostly 2 passive and 1 active regeneration daily Doc temperatures between 560F to 680F, inlet and outlet temps 1030f to 1045f to 1045f to 1065F.

Last November I replaced all egr sensors and clean egr and all the tube and pipes.

[dhafuje]

The scr is original, I let the looked at a while back 6 months ago it looked clean nothing was plugged, I don’t know what exhaust back pressure sensor is and where it’s located, is that outlet Knox sensor? If it’s outlet Knox sensor I have replaced that one in March it showed a code.

The crazy regen practice started when installed new turbo and new software update before that my regen used to be 1 every 3 to 5 days.

[Rawze]

(05-28-2021 )dhafuje Wrote:  ...
I don’t know what exhaust back pressure sensor is and where it’s located
...

cummins quickserv is free... Sign up with your engine ser# and get all diagrams and troubleshooting procedures there. It is called the "Exhaust Gas Pressure Sensor"

and if you paid 12k for a turbo replacement, you got severely ripped off!. What was the part# of the new turbo by the way?.. does it match your engine ser#?. There are different part#'s because they have different exhaust impellers in them for different tier engines.

What does Insite say about what program is in the ECM?

some pics of the regen history?

and the other things i mentioned above>?

... and yeah,... if you don't pull apart those cans and investigate what is on their faces, plugging them up then your just going to keep running yourself in circles. Does not matter how "new" you think they are. You don't get pressure alarms that quickly unless they are getting plugged up.. or you have bad sensor(s)... and you claim you already replaced all of those... so its time to take the things apart and look for yourself.

[dhafuje]

Ok, I found out what exhaust back pressure sensor is, the sensor is new, but I never looked the small pipe, I will
Check that first thing in the morning, I wrench for sensor replacements and cleaning pipes but not the big stuff yet.

[Rawze]

(05-28-2021 )dhafuje Wrote:  Ok, I found out what exhaust back pressure sensor is, the sensor is new, but I never looked the small pipe, I will
Check that first thing in the morning, I wrench for sensor replacements and cleaning pipes but not the big stuff yet.

remove the sensor and plug it back into the harness ... spray moderate amount of brake cleaner into the hole where it mounts... crank truck to see if the brake cleaner comes blasting back up out of the hole.

[tree98]

I'm guessing coolant or oil residue building up on the face of the cans. You need to take them off and have a look with your own eyes and take pics to post here. These problems can be figured out and fixed for WAY less than $35K that's just a crying shame.