I had the same issue with my 2016 but i have 6000 on it dont seam to make a difference just has that growl in the lower end and starting to sound more like a dieselSo just bought a ecodiesel got 2000 miles on it. It is getting loader and starting to hear a growl in bottom or a rough
Some of the fuel may have changed, I usually try to get Cenex Roadmaster when it's available. I also run either Schaeffers Soyshield or Carbon Treat with every tank full. I refrence this study because some additives that a lot of people like to run are not helpful and some are actually harmful.Fuel has improved to the point that todays additives just masked problems, There are new fuels on the market today that were NOT available when this study took place (2007) IMO todays commercially refined Biodiesel is still the BEST fuel for HPCR (High Pressure Common Rail) Diesels for lubricity.
I know bio is popular in the pulling world, Roadmaster is 2% bio/soy enhanced, which is awesome. Beyond that I haven't found a lot of bio commercially available to the publicBiodiesel regulations and the additive package to support Bio fuels,and the open market to sell Bio products.
Tractor pullers are running Bio-Diesel 100% for the additional HP and lubricity. The tractor Puller blend is nasty if it gets on paint or polish surfaces it dulls the finish.