is this a common problem? my car's sideview mirrors tilt down when reverse but don't tilt back up when i put it in drive. should I take it to the dealer? I just got it and it was a certified pre-owned car with the extended warranty

By all means take it to the dealership for the warranty work.

First try manually moving the offending mirror through all its motions then see if it works normally. I had my passenger side mirror actuator replaced 2x under warranty and the 3rd I did myself.

Fed up I moved it by hand and found that the actuator was still good. This past year I had my car in 110 degree heat of the Mojave desert and in single digit temperatures in Kansas this winter.

The common denominator I found in both extremes was that I washed my car a lot in the desert because of the dust and in Kansas because of slush and other road grime that got on it.

I sprayed some lithium grease on the moving parts and so far it's still working.