Mercury Repair Questions? Ask a Mechanic for Answers ASAP
The PCV valve is located either under the throttle body in the y hose or under the intake manifold. Depending on production date.
In either case the easiest way to get to it is to remove the throttle body.
The one in the y hose will be pretty obvious when you get the throttle body out or the way.
The one under the intake will be a little harder to find. There is a fairly large hose going to it (about 3/4 " dia). You will remove the hose and that is where the PCV valve is. It will come off with a pair of long needle nose pliers and it comes out with a 1/2 turn on the valve.
I would suspect that the one in your car is located under the intake.