Intake manifold side (No vacuum)

Rocker cover side

Intake manifold side (High vacuum)

Rocker cover side

Engine condition

Not running

Engine condition

Idling or decelerating

PCV valve

Not operating

PCV valve

Fully operating

Vacuum passage

Restricted

Vacuum passage

Small

Intake manifold side (Moderate vacuum)

Rocker cover side

Intake manifold side (Low vacuum)

Rocker cover side

Engine condition

Normal operation

Engine condition

Accelerating and high load

PCV valve

Properly operating

PCV valve

Slightly operating

Vacuum passage

Large

Vacuum passage

Much large