1997 4.6 PVC valve connection on passenger valve cover

My PVC valve has 2 ports. The bottom port is connected but the top is not. Where does the top port plugs into? It is not capped. Truck makes a loud hissing sound and sucks in strong from the top port. When I plugged the top port with my finger, truck seems to run smoother and quieter.

Help. I searched the web and cannot find any info or pics.

 

You should have a sticker under the hood with the vacuum diagram like this:

 

I see the diagram, but I don't understand it.

 

Maybe someone put the wrong PCV on it. That diagram only shows a single connection. Cap off the extra port and drive on.

 

Yea, it's the wrong valve. I believe you're using a cold climate system PCV valve on an engine that doesn't have the system. A motorcraft PCV is definitly what you want , but yea, you need a standard (one port) 233/238 with that engine...UNLESS your CCS was by-passed for some reason ? Probably not.

 

BTW- Those diagrams don't help much lol. Shows you main line vac. The PCV valve is just a general (non specific). It stands alone in the diagram because it gets vac from the engine (cam cover).