1977-79 528i, 530i, 630CSi, 633CSi, 733i

The crankcase ventilation system on all other models works in the same manner as the 320i system. The difference is in the method of transferring gases from the valve cover. These models draw fumes, vapors and gases directly from the valve cover into the air flow meter and straight into the intake manifold to be burned with the incoming air/fuel mixture.

Fig 1: 1977-79 320i Crankcase Ventilation System

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 2: 1979 5281 Crankcase Ventilation System

Courtesy of BMW OF NORTH AMERICA, INC.