I recently purchased a 2002 F150 with 4.2L V6 engine and a few days later noticed rough idling when it was warm. My shop manual suggests checking the PCV valve but when I did, I found that my truck just has an elbow where the PCV valve should be (there's an elbow on both valve covers).
I talked to 2 Ford parts departments and got two different opinions; the first said that this model doesn't have a PCV valve, which seems unlikely. The second said that it does, but naturally they didn't have one in stock.
So I went to AutoZone and Advance Auto Parts, checked their books and found that the part number for my truck's PCV valve is blank (when a part was not required, the book showed "NR", not blank). The guys at the part desk had no idea what to make of it; AutoZone checked their computer and it didn't show a PCV valve either (though it did for the 2001 model year).
My best guess is that there should be a PCV valve in the passenger-side valve cover. Can anyone confirm this and/or provide the correct part number for the valve?
Believe it or not, I have that exact part ordered from that website sitting in my garage right now. But the hose from the passenger-side valve cover is way too big to connect to that valve, plus the valve has a length of small metal pipe bent around the end the hose goes on and I don't know what to do with them.
I suppose a previous owner could have replaced the hose too.
I ended up buying a new PCV hose from a local Ford dealer because the rubber elbow on mine was pretty soft. When I did, I was surprised to find that there was a plastic elbow where the PCV valve would go. I rigged a hose so I could install a PCV valve instead, and my truck ran like crap at all speeds. When I got home, I removed the valve and installed the plastic elbow and it runs great. So I guess that the 2002 V6 doesn't use a PCV valve after all.
Ford made a change up on the 4.2L and messed a lot of people up. I went to the parts store and was told my 2002 did not have a pcv valve, it will either be that answer or you will get a valve that fits in the valve cover of the older 4.2's (which was posted above). There is no place for a pcv valve in either valve cover, but if you follow the tube coming from the passenger side valve cover to where it plugs into the intake I believe thats where you will find the pcv valve. It is held in by two screws and has two small coolant lines attatched to it. I still need to get this confirmed but I'm pretty sure thats what it is. If you take the two screws out it will easily pull out of the intake. it is different than your normal pcv valve but it is definately an air driven valve and is connected to the top of the passenger side valve cover. The two small coolant lines are a total mystery to me!?
I found out that the 2002 F-150 does have a pcv valve. Although unusual, you will find it on one end of the hose going to the passenger side valve cover but it will be on the top end of the hose and it is a 2" circumference made of metal and has 2 screws. This valve is bigger and looks different therefore unnoticed and will run you about $45.00 at the dealership. Ask the mechanics at the dealership due to the fact that the parts department aren't fully aware. This part costs this much because it's good for 100,000miles.