An exemplary embodiment of the downhole oscillator includes an outer housing at least partially surrounding a motor and a removably coupled eccentric member. The motor at least partially drives the rotation of the eccentric member thereby producing oscillations or vibrations along the outer diameter of at least a portion of the downhole assembly. The motor's action is at least partly facilitated by expulsion of fluid from the drill string through the motor and onto the outer housing interior such that the force of the fluid produces rotation in the motor. Rotation may be enhanced through similar expulsion of fluid from the eccentric member. Alternatively, the fluid may be expelled from the motor and/or eccentric member against the wellbore thereby providing the desired rotation. A method of use may include providing an outer housing, motor capable of producing rotational movement, and eccentric member and coupling same.