It is constantly sucking up fumes from the engine, and it is possible that overtime, gunk can build up and block the suction effect.
Servicing required.....
The PCV is usually located in the valve cover(s). They just slip into a rubber grommet; no tools required.
The PCV just slips out and slips in; no tools required in most cases.
PVC is plastic pipe, It's called a PCV Valve in Automobiles. PCV stands for Positive Crankcase Ventilation. PCV valve. Engine removal is not required on any Automobile, I know of just to change the PCV valve. Some are hard to reach but that is it.
Pull upward on the hose that the PCV valve is in. The PCV valve will pull out of the hose. The PCV valve is located in the valve cover.
No tools required pull valve from valve cover, pull valve from vacuum line, install new valve.
Disconnect the PCV valve tube from the PCV valve.Disconnect the PCV valve electrical connector if it has one.Turn the PCV valve counterclockwise to remove from the valve cover.To install, reverse the removal procedure.
Remove the PCV valve retaining screws. Remove the PCV valve hose. Reverse the process to install the new PCV valve.
About the only emissions equipment on a 68 was a pcv valve.
The PCV valve has a check ball in it, That's what you are hearing. REPLACE PCV VALVE
The pcv valve is on the passenger side valve cover
The PCV valve is located in the valve cover