What is this torus wire coil next to dc motor?
The toroidal coil is probably an EMI or noise filter of some sort. 

It's unlikely the Arduino GPIO pins can supply enough current to run this 5V "engine". You will need some kind of buffer, amplifier  or high-current switching transistor.

Hint: Power the "engine" from a 5 volt DC power supply, measure the current it draws under actual operating conditions, then repost your question with these numeric details.