Hello, I hope everyone enjoyed their weekend. I've been doing a lot of reading about the PCV system in our engines, and the 5.4 3V certainly seems to have a unique PCV system. I've read a lot of conflicting information on several websites, and I'm hoping that someone here can offer an explanation of how it works. I've read that our trucks don't have a PCV valve. I've read that there's a PCV valve under the valve cover. I've read that there are two PCV valves, one under the valve cover and one in the intake manifold. So, there's obviously some misinformation on the Internet. My engine burns oil, and it's evident in the PCV line on the drivers side. Anyway, does anyone have any knowledge of where the valve(s) are, and how the system works overall? Thanks a lot.

 

My 05 is in drivers side valve cover . Built in not serviceable but I cleaned it out real good when I did timing job . Some guys are putting a oil catch can in return to throttle body off of drivers valve cover . Its this return thats dirting up intake ..
There is a thread that a guy is fighting pressure in his crankcase coming out thru the oil fill but I haven't seen the fix .

 

Thanks Redfish. I have the day off tomorrow, so I'll remove the valve cover and clean the PCV valve thoroughly. You're obviously very knowledgeable about your truck, and I'm sure you've taken good care of it. So, I'm curious.... Does your engine use any oil?

 

I don't think it is 'unique'. It's just like most of them except the valve is under the valve cover. I believe on the intake manifold there is a heater. I think it's there to stop condensation from freezing. If you're burning oil then cleaning the PCV valve is not going to fix it. Just my opinion but I think you are wasting your time pulling the valve cover.

 

Thanks Mark. You're probably right about pulling the valve cover. I suppose I'm in denial that it's using oil for a more serious reason. Again, thanks a lot.

 

I haven't tracked it, just add when needed. No drips or anything like that .I don't think I would pull valve cover for just that unless there are other symptoms . I haven't tore a valve cover up to see exactly what's in there seems to be baffled not easy to tear apart . Maybe someone has or will take some pictures of an old one . I would not be worried unless its over 1 quart every 2000 miles . Just guessing . I change every 5k so I know I top off 1 or 2 quarts of syn in between ,I always carry an extra quart . I live in a hot area so the pcv heater circuit doesn't come into play .
I have read a basic explanation of crankcase ventilation and I have seen guys miss hook up vacuum lines and pull excessive oil out of an old engine .
Life is so busy it's hard to track everything ,oh! for the days I used to be bored .

 

How many Qt's/Mile do you get? LOL. Ford would tell you something like 'its within spec' if its isn't > a qt every 1000 miles.

Like @MontanaMark says it's not unique - it's just that the term "PCV" seemed to stick. There is no 'valve' anymore (partly because manufacturers wanted to save the money for that little gizzmo with a steel ball bearing in it that allowed positive pressure in the crankcase escape into intake manifold).

But some clever engineer decided it was a better idea (an I agree with him) to constantly draw "METERED" & "FILTERED" air from inside the air box into the top of the passenger valve cover, through the crankcase, through a filter in the top of the driver's side valve cover, and into the manifold. Never any positive pressure at all, and reduces chances of oil leaks at oil pan / vc/ tc gaskets. Should be called a negative pressure crankcase ventilation system. But as @MontanaMark says, condensation will freeze at the pressure drop point as the moist air is drawn into the IM, so they added a heater in the IM intake tube that the PCM turns on when ambient temp is ~ < 35º.

I personally agree with @redfishtd - "I would not be worried..." unless you need a drain plug in the bottom of your intake manifold. The crankcase should be totally 'sealed' except for the ventilation system. If your throttle body gets oily and gunked up (its drawing air backwards), or if 'smoke' visibly exits the Oil filler tube at idle with the cap removed - it would indicate the 'filter' in the driver's VC is all soggy and plugged up with oily residue and needs t be cleaned/replaced - OR TORN OUT AND REPLACED WITH A CATCH CAN.

Otherwise as @redfishtd (AND I MYSELF) do, carry an extra quart and check regularily.

 

Thanks very much F150Torqued. The engine uses 1 quart per 2400 miles on average. But, if I'm driving exclusively on the interstate, it can use a quart in 1400 miles or so. But, this all gives me a better understanding of how the system works. Thanks a lot.

 

I saw this Makuloco video a while ago and thought it sounded like a good idea even for my plain old NA V6. Just keeps the intake path cleaner.

 

Upper valve cover is left side.