CM870 Turbo Underspeed and Overspeed

[Rawze]

(11-17-2025 )pwhittle Wrote:  Thanks Rawze!

Will do.

just looked at the videos you sent me...

The engine is making full power, no actual power/torque derates, etc.., everything is in order and it is following all data for a non-deleted engine.

However ... boost is a touch low all the time, but not by commands from the ecm. The error is not great enough for a full power/torque derate. etc.. but it is low.

Its a motorhome... I would bet that the CAC is too restrictive (garbage CAC uints are common in motorhomes where engine is mounted in the back of the unit) ... or it very well could be the exhaust is clogging up and getting restrictive ... at least the data points towards this a bit anyways.

That, or the turbo is damaged from carbon stones spitting out of the EGR cooler because it sits too much and carbon and moisture are making carbon stones in the egr cooler,.. then spitting back out every so often, damaging the turbo and weakening it.

.. or perhaps a CAC/boost/egr circuit leak somewhere maybe?.

just my thoughts.