Threaded Mode | Linear Mode

Mluper7 · 02-13-2019, **(Subject: CM870 vibration and black smoke )**

Hi all. I have a cm870 with 565 hp 1850 programming. All stock. Had the motor in-framed 100k miles ago. I drive around Alaska and when the temps get around 20 degrees F the motor starts clattering and runs a bit rough. Lately it's developed a rough growling type vibration when I'm under a load. My boost is up 10 lbs more than usual and in between gears it'll let out a decent amount of black smoke. When I park the truck I'll set it to a high idle at 1200 rpm. It'll idle with the turbo whistling and then after a minute or two the turbo will start to fluctuate and eventually go away. My ideas are leaning towards metering and timing actuators. But I'm here to ask the professionals. Thanks in advance

Mluper7 · 02-13-2019, **(Subject: CM870 vibration and black smoke )**

More on the idling issue. When the truck is running properly it has a crisp tone about her. When the trucks running it sounds like it's in a derate mode. No check engine lights though.

Chamberpains · 02-13-2019, **(Subject: CM870 vibration and black smoke )**

Do you still have the EGR system intact? Factory programming? Do you own or have access to Cummins Insite so you can monitor what the ECM see's?

Mluper7 · 02-13-2019, **(Subject: CM870 vibration and black smoke )**

(02-13-2019 )Chamberpains Wrote: Do you still have the EGR system intact? Factory programming? Do you own or have access to Cummins Insite so you can monitor what the ECM see's?

Yes EGR is intact and operational. I don't have access to Insite unless I take it to Kenworth.

Chamberpains · 02-13-2019, **(Subject: CM870 vibration and black smoke )**

Have you pulled your EGR valve off to see if it's stuck or sooted up? Have you pulled your exhaust back pressure sensor and intake pressure sensor out to see if they are sooted up. Basically pulled the EGR piping and make sure it's clean and clear? It's real tough to troubleshoot your problem unless we know that system is fully functioning properly. You could possibly getting too much exhaust gas recirculation. Because a sensor or pipe is clogged or not reading right.

Mluper7 · 02-13-2019, **(Subject: CM870 vibration and black smoke )**

(02-13-2019 )Chamberpains Wrote: Have you pulled your EGR valve off to see if it's stuck or sooted up? Have you pulled your exhaust back pressure sensor and intake pressure sensor out to see if they are sooted up. Basically pulled the EGR piping and make sure it's clean and clear? It's real tough to troubleshoot your problem unless we know that system is fully functioning properly. You could possibly getting too much exhaust gas recirculation. Because a sensor or pipe is clogged or not reading right.

I did clean the sensors which are all fairly new. The egr valve has less than a year on it as well. I did not pull it to inspect it though. I've also gone over the engine harness

Rawze · 02-13-2019, **(Subject: CM870 vibration and black smoke )**

(02-13-2019 )Mluper7 Wrote: ...
My boost is up 10 lbs more than usual
...

Excess boost can kill an ISX. Anything more than about 38-39 psi on that engine will do things like -- Crack the head, melt a hole through a piston, fret liners prematurely, etc.

There are some known issues with extreme cold climates and the CM870 in particular... I think Unilevers knows more about extreme cold and the CM870 issues, maybe he will chime in and explain it with some detail?.
ref: http://rawze.com/forums/showthread.php?t...5#pid24825

A bad exhaust gas pressure sensor, bad intake pressure sensor, or failing turbo controller can cause some of what your describing through excess boost.

And lastly, there is the possibility of bad/incorrect ecu programming.

Mluper7 · 02-13-2019, **(Subject: CM870 vibration and black smoke )**

Thanks. I do know that the EGP sensor is daisy chained in the harness with the intake pressure, cam positio,n and intake temp. I've gone over all those things which I have had issues with in the past. Every once in a while I'll turn the ignition on and my check engine light will appear and my Road Relay with say Intake Manifold Pressure Sensor Circut Service Soon. I've replaced the sensors and traced Ll the harness looking for faults in the wiring. Sometimes during a high idle after it's been sitting over night it'll miss. Almost as if an air bubble made it to an injector. I was told by one of our Cummins experts that when a actuator starts to go bad that's a sure sign

Rawze · 02-13-2019, **(Subject: CM870 vibration and black smoke )**

(02-13-2019 )Mluper7 Wrote: ...
I was told by one of our Cummins experts that when a actuator starts to go bad that's a sure sign

sound like your "experts" are possibly the typical OEM under-trained parts changers... this is what they should have told you. Starting at Item "C" in this post...
http://rawze.com/forums/showthread.php?t...3#pid34503