Välimäki's first World Rally Championship events came in 1998, in Sweden and Finland, behind the wheel of an Opel Astra GSi 16V.

He contested the 2002 JWRC season in a Citroën Saxo, but only managed a best finish of fifth on Rally GB, ending the year 15th in the classification.

He used the Hyundai Accent on four rounds of the 2004 season, finishing seventh on Rally Mexico.

Välimäki returned to top-class WRC action in 2006, entering three rounds with a Mitsubishi Lancer WRC05.

In 2007, Välimäki won the Finnish Rally Championship, and was runner-up in the following season.