AJ Allmendinger lost the engine on his No. 47 Chevrolet on Lap 33 of Sunday’s Cup race at Sonoma Raceway, not long after winning Stage 1.
Allmendinger was running in 13th when the engine blew, a result of a bad shift. It is his first DNF at Sonoma.
The JTG Daugherty Racing driver, a favorite to contend in road course races, had started the race in fifth and made it to second before drifting back.
Once the race leaders pitted with four and three laps left in the stage, Allmendinger took the lead.
Allmendinger has started in the top five in the last five Sonoma races and not finished better than 14th.
“I haven’t missed a shift on a road course in 10 years,” Allmendinger told Fox Sports 1. “Just me. I was trying to be so patient, so smooth with it. It was unexpected. It’s on me. I let everybody down here.”
Jamie McMurray also experienced a mechanical issue that caused his engine to shut off and lose oil pressure, ending his day.