Positive Crankcase Ventilation: Description and Operation

PURPOSE
The crankcase emission controls prevent crankcase gases from being released into the atmosphere. Instead, the gases are routed to the intake manifold.

CONSTRUCTION
The system consists of an oil trap/seperator, a saftey valve, PCV heater and breather hose. The oil trap/breather housing is attached and sealed to the side of the crankcase, it has a vapor inlet passage, an oil drain passage and a breather hose leading to the intake system. The saftey valve is attached to the breather hose. The PCV heater is an aluminum breather hose connector at the intake boot that is clipped to a metal coolant pipe.

OPERATION
Intake manifold vacuum draws the crankcase gases out of the crank housing into the intake air stream, where they burned as part of the combustion process. The crankcase vapors get drawn through the oil trap , through the breather hose, passed the saftey valve and into the intake sysytem (upstream of the turbo).The trap uses a baffle system to separate the heavy oil particles from the vapors. The oil runs back into the crankcase through the exit at the bottom of the housing. The vapors exit at the top of the oil trap. The saftey valve is used to prevent over pressurizing the intake system, it releases pressure at 0.1 bar (1.5 psi). The PCV heater conducts heat from the coolant pipe to warm the vapors and prevent icing-up.