Coiner will work as the team's defensive assistant coach.
"We're excited to add someone with Charlie's experience and knowledge of the game to our staff," head coach Butch Davis said. "He will work with our defensive line and assist in our special teams preparations.
Coiner is a Virginia native but attended Catawba College for his undergraduate studies and Appalachian State University for his masters.
Blake resigned last week, citing himself as a distraction to the team. The NCAA is investigating allegations that team members had inappropriate contact with sports agents.
One of the agents is said to be an acquaintance of Blake's. UNC also is conducting an independent investigation, which alleges that a tutor wrote papers for some team members.