​Tyler Reddick’s struggles in June carried into July as a major issue unfolded on Lap 135 of the eero 400 NASCAR Cup Series race at Chicagoland Speedway on July 5. The No. 45 car began smoking and leaking oil as it entered turn 3 shortly after a pit stop during a green-flag cycle, leaving the right side of the car coated in oil and fluid and obstructing the windshield. A 23XI Racing crew member suggested the problem originated from something that went through the radiator. Cleanup crews moved in to clear the extensive fluids on “aisle 45,” and NASCAR halted the action for a lengthy caution to allow for the cleanup. The team worked to address the radiator and related issues in the garage, ultimately returning to the track in 36th place, 29 laps down. This incident followed a June that saw Reddick’s strong start stumble with a DNF at Michigan, a late-race tire failure at San Diego, and a power-steering failure at Sonoma, allowing Denny Hamlin to take the points lead after Sonoma—the first time in 2026 that Reddick did not lead the standings. This recap originally appeared in the Nashville Tennessean as part of coverage on Reddick’s radiator setback in the Chicagoland race for SEO context.