No Codes! No Lights!

[JimT]

(06-25-2021 )onebadapple Wrote:  Please keep in mind these nine or so hour apart regens are an actual regen where the idle fuel consumption is about 3 to 4 GPH, the hot exhaust light is on when stopped and I can disable it with the switch. This is not the problem, I can live with this although two years ago with it as a company truck I would see this about once a week or less!
This “halfway” regen goes on for about five or six hours between these and I cannot disable it with the switch but I can stop it with the cruise set button while stopped. While in this “halfway”mode the idle is at 750 rpm and idle fuel is about 2 to 2.2 GPH and no hot exhaust light and the throttle responds like it’s in regen. Hit the set button the rpm drops to 700 from 750, idle fuel goes to .7 or .8 GPH,(it’s out of it) tap the brake or clutch the idle drops to 650, idle fuel goes to .6 GPH, in ten seconds or so you hear the engine change tone and the idle fuel goes to 1.8 GPH still idling at 650 rpm (it’s back in). This is the problem.

Have you looked at the SCR system and sensors? Or hooked up insite with Data Monitor running when this "halfway regen" takes place? What your describing might actually be the system jumping into SCR Warmup mode. (Data Monitor, check aftertreatment operating mode). Low SCR temps, faulty sensors or bad wiring or exhaust leaks could trigger this to happen. Or maybe the SCR has a volcano forming from a DEF Doser Valve leak or the SCR element itself is clogging up? This could also contribute to higher exhaust pressures. Try to see what the inside of the decomp tube looks like, maybe pull the DEF Doser Valve and check for DEF leaks --- The leaking doser leads to crystallized DEF buildup in the decomp tube which will cause exhaust restriction and higher outlet NOx numbers. This buildup can be melted away with higher exhaust temps (I think roughly over 300F is needed at the decomp tube and SCR filter).

[Rawze]

(06-27-2021 )JimT Wrote:  ... maybe the SCR has a volcano forming from a DEF Doser Valve leak
...

reference: http://rawze.com/forums/showthread.php?tid=283

[onebadapple]

Well…I haven’t myself but hoping with two tier 2s and three or four hookups somebody did? Yes I have had it hooked up during this “halfway” regen for a few minutes when I was driving by the day before….twice, to make sure they knew exactly what the problem was. That’s about as far as it went. Did install a new DEF doser somewhere in this mess and hoping SCR was checked. Ok…….as of right now I have about 150 miles on a new DPF and it hasn’t done it’s “halfway” yet. This is not it’s normal behavior as of late. Thinking it’s fixed but not really. When I had the old DPF sonic cleaned five weeks ago the truck ran perfect for five days before it started the “halfway” regens one after another. So, with the new one I am expecting the same thing……we’ll see.
Also, could a leaky CAC be causing ALL these issues? Building extra soot, high diff pressure, slow turbo speed during regen and so on? Just at a high idle, soaked with soap, I get one golfball sized foam after about a minute. Checked it yesterday. Sometimes at full throttle at about 1400 rpm I see 34 on the MP. Mostly I see between 27 and 30 at the same rpm.
JIMT. Complete new wiring. Everything! About $1600 worth installed myself. Some new sensors but which one or two or more could cause it to be jumping into SCR warm up mode?

Thanks for the help!!!

[onebadapple]

Ok, just took apart the decomp pipe and it’s clean except for a few crumbs around the doser orifice. The new DPF didn’t seem to fix it either as it went into it’s “halfway” mode at about 200 miles since new DPF for about 20 minutes. Maybe the ECM has to relearn something? Anyway, it looked promising! Thanks! Anything else anyone can think of? DOC numbers are good I’m told. Sensors?

[JimT]

As to the manifold pressure, you'd be looking at about 34-36 psi for the max. Don't be fooled, Insite will report pressures as inHg instead of PSI. conversion is roughly 2 inHg to 1 psi. Maybe you know this, but it catches some people off guard at first (like me) so figured I'd mention it.

Was the DOC replaced along with the DPF? Your symptoms don't point to this as an issue, but it'll be good to know going forward. Also, it's usually recommended to replace the DOC and DPF as a pair. Depending on the abuse history, 400,000-600,000 is the average life for a DOC/DPF pair.


So, I don't know what these different Tier 1,2,3,4,etc.. actually mean other than they are charging you more and more money. Get yourself an Inline 6 reader and a copy of Insite with any old laptop (all it needs is Windows XP or 7, 10 might work, and a usb connection). $300ish on e b ay and register for a free Cummins Quickserve Online account, then you'll have no use for Tier anything. Never assume any mechanic has done something unless they explicitly say so and even then you can't be 100% sure unless you actually witnessed it. Also, poke around more on this forum for more info on EGR, DPF, SCR and Aftertreatment. There is no "halfway" mode as you keep mentioning. There is Passive Regen, Active Regen and Forced/Parked/Manual Regen (The only real difference between a Parked Regen and a Forced Regen is that the Parked Regen uses a dash switch to "request" a regen, while the Forced Regen is done through software such as Insite and will attempt to run even if some faults are present).

If research isn't enough to figure out which mode is running then you can easily hook up your laptop with Insite running Data Monitor and drive down the road. While the event occurs check the data, it will clearly tell you what mode the Aftertreatment system is operating in. Like I mentioned earlier, your description sounds like it could be running in SCR warmup mode, which would be clearly displayed within Insite. Regardless, knowing the value of this parameter during the event will clarify exactly what's happening and point to the next step(s).


I can't stress the importance of that last bit enough. Without knowing exactly what is happening then you, and the rest of us, are just making blind guesses.


As Rawze mentioned earlier, it's also possible that the aftertreatment system is functioning properly and the engine is just producing excessive soot. Have you tried disconnecting the exhaust from the back of the turbo to see what is actually flowing out? You could also be burning excessive oil and/or coolant which will clog up the DPF with ash. I'm not saying that's your problem, just listing possibilities. These systems are sensitive and depend on each component to function properly otherwise the entire system is thrown off. Since you said components from the old engine were used on the current engine then it's possible that one of them is a factor.

Don't remember if this was mentioned anywhere, but a complete EGR Tuneup is always a good place to start when trying to diagnose aftertreatment related issues. Also recommended to be done on a regular basis to PREVENT common problems. This includes replacing sensors as well as physically cleaning soot buildup from sensitive components, to inspecting parts for leaks and proper functionality.

The users of this site will try to help others whenever possible, however (and i could be wrong here, but...) the main purpose of this site is to help individuals to educate and help themselves. That's where you need to be now. Educate yourself on HOW these systems actually function then stop running to shops who only want to take your money. Take control of the entire process yourself. Some basic tools, knowledge and Insite/quickserve is all you need to methodically diagnose and fix most things on these engines. Don't let your pre-emissions knowledge fool you. MANY aspects of modern engine operation have been affected due to emissions compliance. Not trying to bash your knowledge or experience, but almost every aspect of the modern engine's operation is in some way modified for emissions reasons (sometimes via ECM programming that 99.9999% of people, including the anointed Cummins techs, are completely unaware of).

[onebadapple]

Thanks JIMT for the very informative reply! Ok…eight days ago I installed a new DPF along with the small wiring harness around the DPF pressure sensor. About 2500 miles and no regens except a short one which I believe is the SCR warm-up mode as you described, at the 200 mile mark. None since!!! I believed it is fixed and I can only hope is stays for a while. The DOC was not replaced but, for now, seems to be ok. The only issue I am seeing is the Manifold Pressure is fluctuating. It does go to 35 psi then after pulling for a minute it will settle at 28 or so. After a coast for a minute or two it will repeat. This has been going on since I started driving it as a company truck at 424k. Thought it was normal and now not sure. During a break last week I did a CAC leak down test and according to a Rawze video the amount of decay is ok. Is this fluctuation normal or should it stay at 35 or so in a long hill?
I did buy an “Inline Mini” and got the quickserve account on my Ipad but can’t get much. At Cummins he used the same thing with an Ipad and seemed to get it all. Was told I needed the software only Cummins could get. Fine!!! Guess I need to get the Inline 6 reader, Insite and a laptop or was he FOS?
The folks I haul for just did a SHTF change and I really need to keep moving for a month or two ‘til things settle. For now as long as there is no CELs and whatever regen/warm-up mode it does is at a minimum, gonna run it for a bit.

Thanks Again for all the help!!!

[onebadapple]

Here check this out! This is an ad I found and am making sure it’s what I need. It shows four options and since I don’t have any laptop I am thinking number 3 with 8.5 insite. Should be just a plug and play? Do I need anything else? Some sort of subscription? Thanks!

{link deleted by rawze}.

[JimT]

anything higher than 7.6.2 and you need a recurring subscription along with an internet connection to authenticate each time you run it (i think). 7.6.2 needed a license too, but the internet found ways around that...

--- No software trading on this forum! ---

Based on those prices I highly doubt any of the 8.* versions include a subscription. Further, Option #1 usually runs about $300 on ebay, often from chinese sellers.

I can't speak to the quality of the laptop listed there. Really, any used laptop that can run Windows 7 is more than enough to run Insite 7.6.2. Mine is an old HP bought at walmart in 2007. Does the job just fine.

So, if you can find an old laptop then option #1 would be the way to go, though I can't say if that seller is reputable or not. If you don't trust that seller then try PM'ing Waterloo, he has an ebay seller he usually recommends to people.

EDIT:
Further inspection shows that site ships all orders from Hong Kong. $49 to ship to US. They claim everything includes activation? I guess for $188 + $49 s&h then option 1 is pretty close to the typical going rate. They also state that the laptops are "second hand" with option 4 being slightly better specs than option 3. So, you basically paying an extra $300-$380 for a used laptop which I don't see being worth the cost.