I recently replace the PCV valve, valve grommet, and PCV filter. I get a vaccum from the bottom of the valve, but not on the other side. I can feel a vaccum....but barely. Not like my Haynes manual says...."the suction will be heard as your thumb is released." Does this mean my crankcase is clogged. My oil pressure reads about 40 psi at idle. I don't know if that's normal or not. I do have a small oil leak somewhere.....could this cause loss of vaccum?

 

84,

If you feel vacuum at the valve, that part of the system is working properly. If you reinstall the PCV valve and remove the crankcase breather line, you should feel a vacuum slowly build up while you plug the opening. This will test the integrity of the crankcase seals, gaskets, etc. It takes about ten seconds for a good vacuum to build up, so be patient.

Your idle oil pressure sounds very good. Your leak may be causing a slight loss of vacuum, but you should still feel vacuum build in the crankcase after ten seconds or so.

If you are concerned, you can take some time to clean the engine and monitor it for leaks for several days to help identify the source. A clean engine is always better to look at/work on anyway.