A PCV system is an air pollution control device in automobile engines. PCV stands for positive crankcase ventilation. Automobile makers began installing PCV systems in all new cars in 1963. It helps to recycle hydrocarbon contaminated gases inside the engine (blowby) back into the engine's combustion process. [Ecology A to Z; P. Fleisher; 150-161; 1994;Dillon Press; New York] [Occupational Environment; S. DiNardi; 1320; 1997; AIHA Press; Fair Fax, Virginia]