How does a PCV valve work on a 1987 jeep wrangler?

Answer 1

PCV stands for positive crankcase ventilation. You crankcase needs to be ventilated to keep pressure down. Too much pressure will cause excessive oil consumption by forcing oil past the rings into the firing chamber thus burning oil. In the old days the crankcase was vented to the atmosphere causing polution. On todays engines it is a simple ball valve that opens when the engine is running. The pcv ball is sucked open to allow the excessive pressure to be returned to the intake manifold and it becomes part of the fuel air mixture. If the valve is stuck the crankcase pressure builds up and forces oil past the rings as if no vent were there. Checking the pcv is easy. Just pull it out and shake it. You should hear the ball moving back and forth in there. If you don't you will need to replace it.