. . . 2016 Ram diesel with 40,000 miles. I got an exhaust system regeneration notice. the notice cleared and then my check engine light came on. I have 2 generic questions. The dealer charged me $220 for a stationary desoot. Was this necessary? . . . .
Yes. If you had not performed the regeneration process, your engine would have become "constipated" and would not run properly. Any diesel engine sold for use in the United States (either on-road, agricultural, construction, off-road, etc) must meet very stringent emission standards for exhaust particulate matter (soot) and NOX (oxides of nitrogen). To meet particulate reduction manufacturers have installed DPF / diesel particulate filter traps in the exhaust immediately downstream of the turbocharger. It traps the small soot particles as the engine runs. When the filter reaches a capacity level of 60 - 70% of maximum allowable the PCM (powertrain control module) starts a dynamic / active regeneration process. It will inject extra fuel on the exhaust stroke of each piston. This extra fuel combined with remaining oxygen in the exhaust raises exhaust gas temperature to the range of 1100 - 1300 def F. This high temperature oxidizes the soot particles and reduces them to small amounts of ash. When the contamination level drops to below 10% in the filter, the process ends. It will do this repeatedly over the life of the DPF element.
A problem will occur if you do frequent, short trip driving where the DPF reaches the threshold of 60 - 70% contamination level and starts the regeneration process. Slow speed driving or engine stop causes the exhaust temperature to drop below 1100 - 1300 def F and the regeneration process is interrupted but the contamination level never arrives at the 10% level. If you do this often enough the contamination level in the DPF will reach 90% or greater and that is when you get the messages about service regeneration needed. See this short video that explains DPF regeneration. The video is tailored to British cars. One thing that may be unique to European diesel standards is the flashing DPF symbol on the dash. U S standards may use a text message on the dash but I am not sure about that particular point.
View: https://www.youtube.com/watch?v=aMKpo74P6SE
. . . . I also had multiple issues (intake throttle valve, 2 gaskets and maybe a PCV valve). . . .
I do not think these issues are related to the diesel exhaust treatment system (DPF regeneration). But leaky intake system gaskets can cause problems with the proper air mass intake which can effect proper air - fuel ratio management and lead to higher than expected diesel exhaust emissions. Diesel exhaust treatment of DPF regeneration and DEF (diesel exhuast fluid) injection for NOX control have very narrow and specific parameters for proper operation.
. . .Is this going to be an ongoing issue with the newer diesel? . . .
Proper operation and driving of the diesel engine by the operator with DPF and DEF treatment is critical. If you do frequent short trip driving where the dynamic exhaust gas DPF oxidation / regeneration is NOT allowed to complete you will have this problem again. I would suggest investing in specific monitoring devices for diesel engine exhaust. These devices plug into the OBD II port and give information from the PCM about the regeneration process. If you know when the regeneration process is about to start you can continue to drive the vehicle at highway speeds and allow the process to complete. Diesel powered vehicles require a "little more savvy" by the driver today to avoid expensive maintenance service.
. . . .This is my 6th cummings and I have never had these types of issues . . . .
Your most previous Cummins diesel before your 2016 was before model year 2010. It did NOT require this expensive, complex, and potentially trouble prone exhaust emission treatment equipment.