w124 Memory seat motor noise
 

I noticed today that when I'm using my seat memory function (1 or 2) to adjust the seat the motor moving the seat base makes a noticeably different sound than when just using the standard seat power controls. The motor is a lot louder when using the memory function than when using the standard seat controls.

Is this normal?

Also, it looks like my memory function (1 and 2) don't adjust the seat back angle, so I'm guessing something is broken? What could it be? I did some searching but no luck, not really sure what terms to search.