4 Runner 4WD V6-180.5 2959cc 3.0L SOHC (3VZ-E) (1989)
Positive Crankcase Ventilation: Description and Operation
The Positive Crankcase Ventilation (PCV) system provides more complete scavenging of crankcase vapors. Fresh air from the air cleaner is supplied
to the crankcase and mixed with blow-by gasses then passed through a positive crankcase ventilation (PCV) valve into the intake system. Once inside the
intake system the mixture is added to the normal fuel/air charge and burned in the combustion process.