A mechanic was seriously burned Tuesday morning at a Queens auto body shop when his co-worker started the car he was repairing, an FDNY spokesman and sources said.

The man was working near the gas pump of a car — and working with gasoline — at AMJ Auto Repair on 37th Avenue in Long Island City shortly before 8:30 a.m. when his colleague turned the ignition key, sparking the burst of flames, said a source familiar with the case.

The victim suffered burns to his chest, face and neck and had difficulty breathing, an FDNY spokesman said. He was rushed to the burn center at NewYork-Presbyterian/Weill Cornell Medical Center in serious condition.