X15 2450 low power high fuel consumption

[Will144]

Hello everybody, I have an x15 2450 down on power ( feels sluggish) and fuel consumption is way up. About a month ago, after having a week off, I started my truck and had the low coolant lamp on. I thought that it was odd because before I went on vacation I looked everything over and fixed a couple of things. I topped it off hooked up when I started driving I had a cloud of steam behind me. It didn't occur to me right away something was very wrong but I turned around (put 8 miles on) by the time I got back to the yard. I pulled the pipe off the back of the egr cooler and found coolant! Could get in to the stealer for a week so I figured I'd conquer it myself. Pulled the bellow pipe off the front pressurized the coolant egr cooler filled up, ordered part. My old cooler was the square style was told it was superceded to the round style and I would have to get a different calibration because of it. Removed doc and dpf, found coolant , had baked at local stealer. Removed egr, mixing tube, and cross over pipe cleaned them out. Replaced delta p, cleaned exhaust pressure sensor housing and tube replaced sensor also, along with imap. Reassembled got the dealer to calibrate it thought I was good to go. Loaded a headed out.

Well, it wasn't long before I started realizing something isn't quite right, about halfway through the next day power didn't seem like it was there when I really put my foot in it. Finished my round when I got home looked over it again found exhaust manifold leak at the joint. Bought a slightly used manifold off a new truck from local demandator hack. Still same symptoms. Did a leak down test drop 8000psi in a minute. Relief valve checked good so I started capping injectors. Found number three to be leaking retorqued tube and wow drop 500 psi in 5 minutes. Also I think I get an occasional miss however I can't pin point with a cutout. Will run on all six by themselves (cutting out the other five). Ran over head, nothing seemed like anything was out of adjustment. Barring engine over I could hear hissing on one cylinder thought It might be intake valve but when I put my ear to the intake hole I couldn't hear it sounded more to be coming from crankcase felt the same as other 5. Next I was thinking turbo damage because of coolant removed actuator cycled very easy no hangup. Removed turbo to inspect turbine housing all looked great.

I'm really stumped, I am one that never asks for help, I've always been able to figure things out. Yeah, I 've shot the parts Canon at things in the past, but with the cost of parts for these you just can't. I have noticed the egr valve likes to be open anywhere from 70 to 80 percent running down the road seems high, also intake nox seems high but I have nothing to compare it to. I'm almost wondering if the injectors are [/align]fueling right I have heard these have injector issues that will melt the dpf. Could the cooler be a symptom of a bigger problem. There is a shop nearby with a dyno, maybe put it on that, possibly pull the exhaust pipe check for smoke while cutting injectors. Or could it be the new calibration. Any thoughts?

[tree98]

(11-19-2023 )Will144 Wrote:  My old cooler was the square style was told it was superceded to the round style and I would have to get a different calibration because of it.......Reassembled got the dealer to calibrate it

I wonder what program they put in it? What program did it have and which one did they put in? The original program will be the numbers printed on the outside of the ECM, it's the "ECM code" then you can see what they put in it by looking at the very top top top of the screen when hooked to insite.

[JimT]

After your thorough troubleshooting description my first thought is also to verify the ECM program. Also go into insite and double check all your settings to make sure something wasn't turned on that was previously off. Some of the so called efficiency settings could contribute to the feeling of power loss.

[Will144]

Just looked up the code in work orders. New one is KW10431.06 the old one is KW10091.04. I asked the dealer to put the old one back in to try it. They said they couldn't. I'm not sure how to do that part myself. I'm using a company truck until I get it fixed right. Just don't need to burn it up by driving it when it's sick.

[Rawze]

(11-19-2023 )Will144 Wrote:  Just looked up the code in work orders. New one is KW10431.06 the old one is KW10091.04. I asked the dealer to put the old one back in to try it. They said they couldn't. I'm not sure how to do that part myself. I'm using a company truck until I get it fixed right. Just don't need to burn it up by driving it when it's sick.

The differences between program KW10091 and KW10431...

== The 'Road Speed Look-ahead' feature is ON in the KW10091, but is OFF in the KW10431.

== The KW10431 program allows for slightly more fueling between 1600 and 1900 RPM with regard to base engine operating modes, SCR and DPF temp control modes, and for After-treatment oxygen limiting situations.

== The KW10431 program asks for (about 5%) less EGR gas between 1000 and 1200 rpm below 4,000 feet altitude.

== The KW10431 program asks for (about 12%) less EGR gas when it is running in engine operating mode 13 (SCR moderate warm-up mode). It calls for more aggressive charge flow (slightly higher boost) in this same operating mode, and it also has sightly higher fuel pressure requests in this mode as well.

Aside from what is mentioned above, the main EGR requests are identical.

== Injection timing has been reduced (by a couple degrees.. which is a medium-large change for a CM2450) in 3 of the engine operating modes. These modes are ...

++ (mode-A0) cold-start/engine overload.
++ (mode-13) SCR moderate warm-up mode.
++ (mode-3) extreme altitude EGR+ operating mode.
In all other operating modes, the injection timing is the same.

== The torque fuel conversion has been altered in several engine operating modes. This will directly effect 'how the engine accelerates and feels'. The changes are...

++ (mode-A0) cold-start/engine overload: The power has been made MORE aggressive in the KW10431 program.

++ (mode-A1) low-altitude EGR+ mode: The power has been made LESS aggressive in the KW10431 program, and will feel slightly weaker.

++ (mode-2) high-altitude EGR+ mode: The power has been made MORE aggressive in the KW10431 program, and will feel slightly stronger.

++ (mode-3) extreme-altitude EGR+ mode: The power has been made MORE aggressive in the KW10431 program, and will feel slightly stronger.

++ (mode-11) agressive SCR temperature management mode: The power has been made LESS aggressive in the KW10431 program, and will feel slightly weaker.

++ (mode-13) SCR moderate warm-up mode: The power has been made quite a bit LESS aggressive in the KW10431 program, and will feel moderately weaker.

== The coast manager idle speed used for auto-trannies with 'coast' feature is set to 500RPM in the KW10431 program and set to 600rpm in program KW10091. Personally, I think that 500rpm is too low, and will cause the top-end to easily get starved of oil in the engine while in this state.

== There are quite a few changes in the mis-fire detection manager between the 2 programs. The changes are not subtle.

== In the KW10431 program, there are extra (and some more aggressive clamping) EGR flow monitors/restrictions that are switched on in the UFM (Universal Flow Manager) circuit. This is extra hi-flow, low-flow, accel limiting, and other limiting based no these extra flow restrictions. There is also a EGR flow 'noise restriction' that is set much more intolerant in the KW10431 program. I suspect these changes would negatively effect acceleration rates by some degree .. but that is speculation.

== The engine CPL changes from 5479 (KW10091 program) to CPL 5869 (KW10431). The CPL change seems to be related to a different fuel code par# mostly.. however all fuel pump, etc. settings are identical to both programs.


All else in the programming is identical between the 2. They are 100% compatible with each other as a whole, but the KW10431 does seem to have more aggressive EGR restrictions, more sensitive cylinder mis-fire detection, and slightly less power output settings for some of the engine operating modes, as mentioned above.

[Will144]

Wow, that is interesting information. This leads me to believe the issue probably isn't the calibration. As I was running across Montana today I plugged in to the truck I'm using just to try to compare the two watching data. This is a x15 2350 in 565 1850 torque so maybe like comparing apples to oranges. Anyway I notice egr commanded and measured maxed at 45% open, mostly hanging around at 20 to 30% range. So now I'm wondering what conditions call for the egr valve to open more. Like I mentioned, mine seems be hanging out at 70 to 80%. Also I noticed the throttle valve doesn't close on this one going down the road.

[windowrattler]

You could check for boost leaks, egr differential pressure sensor tubes and exhaust pressure sensor tube. We had a school bus recently that a boost leak and egr diff press sensor tubes was messing with readings. The ecm would slowly keep on opening the egr till it would get to 100%. Fixing the boost leak made it slower to climb to 100% but the mostly clogged egr dps tube cleared out the issue all the way.

For egr from what I know the ecm is after a certain amount of egr flow. It calculates how much flow is happening and if less than it wants it opens the egr valve more. It will open it until it gets to it's commanded flow rate.

[Will144]

(11-20-2023 )windowrattler Wrote:  You could check for boost leaks, egr differential pressure sensor tubes and exhaust pressure sensor tube. We had a school bus recently that a boost leak and egr diff press sensor tubes was messing with readings. The ecm would slowly keep on opening the egr till it would get to 100%. Fixing the boost leak made it slower to climb to 100% but the mostly clogged egr dps tube cleared out the issue all the way.

For egr from what I know the ecm is after a certain amount of egr flow. It calculates how much flow is happening and if less than it wants it opens the egr valve more. It will open it until it gets to it's commanded flow rate.

Yes, I have cleaned the dps tube and replaced the sensor. Also replaced exhaust pressure sensor and cleaned housing and tube. Soaped the cac and pressurized it. I know I'm overlooking or missing something just need to figure out what. That's what brings me back to thinking, fuel not burning efficiently maybe? It just seems weird that it showed up after the cooler failure. Stealer said egr cooler is rare, so I'm kind of wondering what caused it. Could ithe cooler have over heated from to much egr flow to begin with?

The dealer said I could bring it by for a drive. He said they could log and send it to the manufacturer. I really don't want to fall down that rabbit hole.

[tree98]

The first thing I would do is put the original program back in and see if there's a noticeable difference.