X15 300K mile problems

I have a 2023 Cummins with 233k miles and haven’t had one single issue. I change the oil about every 30k Mobil Delvac 10-30 (used to do every 20 but stretching them out now).
Fuel filter (spin on) at oil change time. Davco fuel filter as needed..est every 10k. Grease about every 5k or after a cross country trek.
Grease and Davco filter I do myself. Aside from filters I really don’t carry any spare parts.

My 2021 Cummins I had to replace the turbo speed sensor early on. No other issues in the short time I had it..stolen with 115k on the clock.

Not sure I agree with it but Cummins recommended running the top end at 500k.

 

Take a look at the engine hours. May give you a better point of reference than miles.

If you would need to travel to check the truck out, may just want to ask for a picture of the engine labels.

Searching the net with the VIN number can yield some interesting results, A friendly dealer may also do a search and get you some basic build spec and warranty history.

 

If it’s the updated 579 with the narrow grille it should be EPA21. I’d say find out what all has been done under warranty. Also there’s a recall on the shift stalk but no parts are currently available. You might want to find out if the shifter is original or if it’s already been replaced once. The new ones will be an updated design.

 

Didn’t mean a rebuild at 500k, just doing a valve adjustment.

 

I’d do one around 75k ish and than another around 400-500k.

 

It would depend on the the how the truck is set up.

Base line for me is over the road truck. Most over the road trucks average about 50MPH over their life time. I would expect to see about 6000 hours of run time at 300,000 miles. If it's under 6000 hours it would raise flags for me.

Real world steps in at that point in the form of idle hours. I would consider up to 7000 hours not bad if the truck has an APU. Some major carriers give drivers financial incentives to keep idle hours under 20%. Idle hours are kinda hard on the emissions system.

If the truck has a PTO or does not have an APU it would most likely throw that number higher.

My knowledge starts to get vague/falter at that point.

Link to Cummins quick reference service guide:
https://mart.cummins.com/imagelibrary/data/assetfiles/0032935.pdf