While driving at maintained speeds of 45+, with and without cruise control, the engine will rev up 1000-4000rpms, settle back the rev again, repeatedly, without changing traveling speed. This used to happed only on inclines or againts a head wind, but now happens continually.
Can you hear the engine actually reving up or is it just noticed on the tachometer. You don’t mention whether this has a manual or automatic transmission. Include vital information like make, model, year, # cylinders, configuration, mileage, CEL ‘on’, OD light ‘on’ or ‘blinking’, what gear you are in, etc. Give as much information as you think we can assimilate and we will respond with replies that apply.
Further information:2002 dakota quad, 4x4, V8, auto. trans., 118,000miles, always happens in 4th gear, where overdrive is normally operating. Yes I can hear the engine reving up. No other check lights blinking. Thank you!
It sounds like the torque converter lockup is disengaging. The converter lockup on my 95 Dakota would engage around 47 mph. The TV/downshift cable may need adjustment, it may be too tight.
This is a good resource for all things Dakota.
I appreciate your advice and will dig into this further.