Dimel served an integral role in leading Kansas State to a 21-5 record from 2011-2012. The Wildcats finished in the Top 15 each season and quarterback Collin Klein was a finalist for the Heisman Trophy. In 2012, Kansas State was crowned champions of the Big 12 and earned a trip to the Fiesta Bowl. During his first stint as part of the Kansas State coaching staff, Dimel was instrumental in four consecutive Top 20 final rankings. As the offensive coordinator in 1995 and 1996, the Wildcats won 19 games and finished #6 and #17 in the coaches' poll is respective years.
From 1997 to 1999, he coached at the University of Wyoming, and compiled a 22–13 record. At the time he became head coach, he was the youngest head coach in Division I-A. Based on the strength of that coaching job, he became the head coach at the University of Houston. From 2000 to 2002, the team compiled an 8–26 record. Dimel, however, inherited a difficult situation and recruited many of the players that fueled UH's resurgence under Art Briles.
In 2004, Dimel was a graduate assistant at Kansas State, his alma mater. He had previously been an assistant there from 1987 to 1996. In 2006, Dimel became the tight ends coach at the University of Arizona. In October 2006, he took over as running game coordinator for the team as well. After his promotion, the Wildcats beat three top 25 teams.