My car typically spins at about 1900 rpm at my typical highway cruising speed, which is 73-74 mph. Lately, it's been switching between 1900 and 2200.

When this happens there is no jerking and no change in engine pitch. It is NOT downshifting to third--that produces about 2600 rpm. There is also no relationship to the DoD.

Any ideas?

 

This seems to be my "go to" suggestion anymore but..... Check the MAF..

 

By the way it sounds your transmission torque convertor isn't going into or shifting back and forth between lock up mode . I had same issue's with a older car right after the trans was rebuilt. Not sure how too test or if a scanner would show you this information.

 

x2. it does sound like it's locking and releasing on you. Some OBD scanners can show the state of lockup, my HPTuners software shows me when it's happening.

Another thing could be the cold. I know all across the country we are experiencing below average temperatures. The colder air could be messing with some of your sensors and the car is just making adjustments.

 

See, this is exactly why I mention the MAF.. I thought this, was told by another mechanic this is most likely the issue, then finally brought it in for a full diagnostic (cause trans is still under warranty) and turned out to be the MAF..

 

A lot of the times the MAF will do it while idling though, and not in highway speeds where the converter lockup clearly would be happening.

It's cheap and easy to clean the MAF, and should be considered, but it does sound more like the converter lock up based on the conversation.