When cruising at low rpm's in a high gear with light throttle pressure engine rpm's will raise and fall consistently. Will also do it at times when it should downshift. Mostly happens in 5th gear sometimes forth gear. Changed fluid and filter last year. Any help would be appreciated.

 

Locking torque converter doing its job. Try driving faster.

 

yeah that makes it go away but it never did this before just started maybe a week or two ago. Maybe a transmission speed sensor or something? I had a diesel truck that did the same thing, It had a bad engine speed sensor.

 

Could be the start of your torque converter going bad. Have you tried Sport mode versus regular mode? That should change the lock/unlock characteristics somewhat.

Bob

 

Yeah, in sport mode it does it less often, the rpms have to be low for it to happen