S15/T15 Sonoma P/U 2WD L4-2.2L VIN 5 Flex Fuel (2001)
Positive Crankcase Ventilation: Description and Operation
Crankcase Ventilation System Description
General Description
A crankcase ventilation system is used to provide scavenging of the crankcase vapors. Blow-by gases are passed through a crankcase ventilation oil/air
separator into the air cleaner outlet resonator. The oil/air separator is inside the valve rocker arm cover and allows any scavenged oil to be returned to
the crankcase.
Operation
The only flow through the oil/air separator is the combustion blow-by, as there is no fresh air inlet to the crankcase. The primary flow of blow-by into
the separator is through the openings inside the valve rocker arm cover. The oil/air separator causes oil, which may be suspended in the blow-by gases,
to be separated and drain back to the crankcase. The blow-by gases are then drawn into the air cleaner outlet resonator by normal engine vacuum and
burned in the combustion process.
