The throttle valve (6) is partially opened or fully opened.
The air flows very rapidly through the vent line(5)s connection(D) and the intake air duct when full-load at partial load.
Consequently, most of the low-by gases are supplied to the combustion chamber through the timing gear case cover(15), chain housing(17), oil separation chamber(3), vent line(5), throttle valve(6), and intake manifold(8).