I have a 2019 f-250 6.2l that exhibits intermittently a momentary growl under tow along with a 200rpm surge at several different RPMs in cruise. No other symptoms during these intermittent growls. For example, locked cruise in on level straight away pulling 32ft RV and about every 20 to 30 sec, this anomaly happens. I know the truck does a great job in adjusting torque converter in all load signatures but this seems almost an odd control "tick" that may be due to an input/feedback sensor or something.
I searched and did not find history. Anyone aware of this issue with any recommendations? Thanks in advance!

 

Can you be a little more specific as to where you think the growl is coming from and loudest ?

 

Sorry, BTW its a 2wd Crew Cab w/around 60k, the exhaust system is factory and I have a small hole in the final muffler near the right rear tire. This started about 6 months ago and I hear the growl under the cab, sounds like maybe a part of the exhaust but not sure if anything in the torque converter makes noise when not down-shifting but spiking the rpm 200rpm for about 1 to 2 seconds then back to normal smooth state. If this is just a resonance thing I'm hearing, the exhaust repair should fix that. I still don't know why it is adjusting rpm momentarily when running on smooth, level road with no wind and otherwise holding steady rpm. I hope this helps.