12' 6.7 engine bucking at low rpms
I have a little over 10k miles on my truck. The past week I have noticed my engine "bucking" at low rpms. it mostly happens at low speeds when i completely let off the gas and am coasting at 1500+- rpms. you can hear it rev up and down and it slightly shakes the truck. it does this a lot at red lights when slowly moving up. the first time i noticed it i actually watched the rpms gauge jumping up and down in a 100 or so rpm range. this past time i dont think my gauge moved any. truck runs great and strong as ever. no other problems noticed. what could this be? it seems so minor idk whether to be worried or not. i have all my parts in to do my delete but am thinking i might need to take it in to the dealer to have this checked out first?