I can't be sure, but I think that the pot is a "wire-wound" one and these can be strange beasts
One reason is the very low resistance - it is obviously made to "drive" an old mechanical meter directly and these usually requires quite a bit of current in the automobile world - a more "modern" pot would not like high current.
The second is the strange value change - if the wires aren't consistent wound around the former, you will get irregular changes as the angle changes and sometimes even no connection along the way => this type is crap in connection to a MCU ....
If you do have to change it - use one that has a max resistance about 1KOhm. and a travel as few degrees more than needed as possible (unless you get down to less than 10-15 degree extra).