Well, I made it to Page 92. I was hoping for that 'silver bullet', especially since the rate of growth of this thread has slowed down so much. Here's what I think I know:
I have a 3500SRW SO 6.7. I took delivery in January of 2022, in the days when chips were in short supply. I routinely tow a bumper pull horse trailer, weighing about 3000 lbs empty, 4200 with one horse, 5400 with two and 6600 with three horses. I also tow a 14,000 lb 5th wheel, typically two or three extensive trips per year, like up to Canada, over to Florida, out to Montana etc. In between the towing trips it's a daily driver with lots of short trips for various typical errands.
-My truck had infrequent regens for a long time, like 3 1/2 years and 68,000 miles or thereabouts. Given that and all the stories here, it appears that the environmental systems will gradually lose ground and build up residual soot in the DPF, with the biggest factor being the duty cycle. While I was driving around solo up in Canada a few months ago, I got my first forced regen that had the message to 'continue driving'. It happened again about a month later down here in Texas.
-There are so many potential causes and contributing factors that it seems unlikely a single root cause will ever be identified, except maybe in the big bucket know as software. There is clearly something common to the 2022's, which could imply one or more sensors that may have been sourced from a 'secondary' source due to the supply chain issues going on at the time.
-It looks to me like the time it takes to hit the 'very frequent regen' situation is largely dictated by duty cycle. I got further than many as my duty cycle has more towing miles than many others
-I treated the truck with Archoil 6400D after the second 'keep driving' regen. It definitely helped. I'm guessing that that more stern active message is triggered when the DPF soot level hits some key level, perhaps 50%. I think focusing on the displayed soot level from the differential pressure transmitter is misleading at best. I don't plan to put any significant focus on it.
-I began treating with Archoil 6500 and I'll continue for now but I think the jury is still out. The truck is showing signs of better mileage, but we all know how hard that is to quantify.
I really like my truck. I just hit 75,000 miles and I have a 100,000/7 year warranty. It looks like I'll finish my warranty in less than 2 years. Here's my plan:
-Treat with Archoil 6400D if and when I get another 'keep driving' regen message.
-Watch my oil level closely, and shorten up my oil change interval. How often I change it might be dictated if I find my oil level is rising.
-Whenever possible, use the wife's car or my motorcycle for the short around town errands, hence improving the duty cycle.
-Monitor this thread and/or others like it in hopes that something concrete is identified that will improve the regen performance.
This will hopefully get me through to the end of my warranty, and I'll assess options from there. In the meantime, something new has popped up. I started getting a new message that pops up and chimes every time I start the truck. it simply says "Perform Service". The dealer service writer says that message triggers a number of diagnostic tests that typically take from 2 to 5 days. I have an appointment to leave the truck with them on Tuesday the 23rd. I'll write up my experience in this thread, assuming it's relevant. I don't recall that particular message being mentioned in the previous 92 pages.
