Cm870 acting dumb.

[Lonestar10]

My dad has a 07 Kenworth t600 with a cm870 13sp overhauled last January turbo is also only a year-and-a-half-old the turbo vgt control module is only 3 months old. Stock programming injectors and head replaced with overhaul. Also he did find some leaks on the airline from module to the turbo and fixed them
EGR valve is new and supposedly he's replaced the typical three sensors you just doesn't remember which one was when.

Basically he's having an intermittent issue where he can go into a hill and have 38 lb of boost and perfect 800° egts or he goes into a hill and has 30 lb of boost and almost 11 hundred degree egts the truck is also running extremely warm it's basically having to run the fan constantly to maintain temperature. There has also been a few instances when it's idling suddenly there's blue or bluish gray smoke coming out of the exhaust and it smells terrible not like fuel but something else and burns your eyes. He says no abnormal oil usage and he doesn't add any water.


Anything he should look at guys I'm not sure on the 870 what could be causing his issues and it's not as diagnosable as the 871 with electronic actuator for me


Thanks!

[Rawze]

thats the symptoms of it going into a turbo derate for one reason or another. maybe unilevers knows more about it, i think he has mentioned cm870 derates for turbo a few times on here.

some derates can only be seen and checked "why" by using the CT software.

[Chamberpains]

Make sure the EGR pipe from the cooler around the back of the block is all intact and no broken or loose clamps or hoses. Typical 3 sensors are exhaust pressure sensor, intake pressure and intake temp. I replace mine annually. But i believe the differential pressure tubes have sensors and they soot up along with the tubes. Make sure they're in good clean working order. It's been so long since i pulled all that junk off, i cant remember what all was on it originally.

[hhow55]

I'm leaning toward's the exhaust pressure sensor.

[Lonestar10]

he was getting exhaust pressure sensor codes a month or 2 ago so that one has been changed along with barometer sensor about 6 months ago ages of imap and egr dif idk. he says hes pulled egr sensor and cleaned it and the tubes were replaced with overhaul.