What does a PCV valve contro in ford trucks?

Answer 1

PCV stands for positive crankcase ventilation. It prevents an over pressure condition in your engines crankcase that could cause oil to be forced past the pistin rings into the firing chamnber. If your PCV is clogged you will probably see increased oil useage and on some vehicles gas mileage may be affected as well. On cars prior to PCV there was an open tube that vented excess pressure over the side. With PCV the pressure is vented into the intake manifold and used as part of the fuel/air mixture.