His Nationwide Series pole-winning speed on Friday afternoon was disallowed after his car failed post-qualifying inspection. Officials found an illegal open cooling hose that went into the cockpit, a violation of Rule 20A-2.1J.
He dropped to the rear of the field, No. 42, for the start of the Jalapeno 250 on Friday night but is still credited with winning the pole. However, Ricky Stenhouse Jr. will start from the No. 1 position.
NASCAR spokesman Kerry Tharp said further penalties might be announced next week.
Dillon was also penalized last weekend when his race-winning No. 3 Chevrolet failed post-race inspection at Kentucky Speedway. He still got to claim the win, but the points penalty dropped him to second in the championship.