the foam was under the air filter and it looked like vanilla pudding, no joke! (I have pictures), I have since then, stuffed a peice of cotton in the tube under the air filter...I am looking for the answer about the foam...

Thank you
Scouter1

 

if it is a302 don't know about 351w but there is a screen under the pcv valve be sure to replace it if you have oil leaks this might take care of them

 

This thread has been very useful. My truck has been idling badly/stalling so I figured time to change the PCV valve (94000+ miles). I ran into two problems. I was reading Haynes Repair Manual. It is kind of cryptic about the location of the PCV valve on my year/engine.

(1) My truck has a Crankcase Vent from the oil filler cap (sticks out the side), which makes its way over to the Air Filter box. If you open the Air Filter Box, you can see where it connects to a tiny little filter (I replaced that too). I figured that the PCV somehow attached along this hose, but after reading this thread I discovered I was wrong.

(2) The PCV valve is indeed located on top of the Valve Cover on the passenger side at the rear of the engine, beneath the Intake Manifold (very close to the firewall). I needed a telescoping inspection mirror, large flashlight, and a lot of patience to find it. You can't see it directly. It plugs into the top of the Valve Cover (into a rubber grommet) and runs via a short hose straight up (maybe 5-6 inches) to the back of the Intake Manifold, where it plugs into a L-shaped metal fitting (which is threaded into the Intake Manifold).

I was able to reach back there (by climbing on top of the engine) and pull it out by hand. I also removed that short hose (to ensure it wasn't clogged or cracked). The replacement PCV Valve fit back in neatly, but the short hose was hard to get back on. Fortunately, I didn't damage the rubber grommet on the Valve Cover and was also able to reuse the short hose. I re-installed the short hose onto the PCV Valve before I installed the PCV Valve into the top of the Valve Cover. That made it easy to bend the short hose back onto the L-shaped metal fitting sticking out of the back of the Intake Manifold (after I had the PCV Valve in place). Let me tell you, this was not as easy as I thought it would be. But well worth the effort, as my truck is running great now (although the old PCV Valve was in pretty good shape).

Bottomline: This thread helped me find it. Thanks for all the great information. I'm just adding a bit more information from my own troubleshooting for the next person whose looking for the PCV Valve! Good luck (hope you have long arms).

 

I needed to replace the PCV valve on my 90 F150 5.0L because of rough idle and oil in the air filter. For such a simple little part, it was a royal pain to get out, and nearly impossible to get back in. So, I went out and found a right angle brass hose connector thingy kind of like for a water pipe. It had a "jagged" hose fitting in one end, and I ran a pipe nipple in the other. Using the Ford grommet (new) I installed the grommet, and then the pipe angle. The teeth made it easier to get the angled deal in than the old valve. I ran a length of hose off the angle (with a clamp, all pre-installed) to the firewall, mounted the PCV valve there. Another hose and clamp runs back to where it went originally, and now I can replace the PCV valve in 20 seconds, and with no swearing.

 

now on mine there is a screen down below the pcv valve mine was blowing oil out the seals even with the new pcv and a buddy of mine told me about the screen and we took the plentum back off and sure enough there was a screen under the pcv and it looked factory and I changed it and my oil leakes almost stopped.Just thought you would like to know

 

Judge, how hard was it to get the screen out? Is it down in the valve cover? Any chance of dropping it in by accident? I'll have to check mine out.

mcgrew and dwvalascho, did the pcv alone actually improve the running of the engine?

scouter, the foam is just moisture in the oil. It is often caused by making lots of shorter trips, never really letting it warm up to cook out any moisture. If you see it on your dipstick, change the oil. Not a big problem, but I wouldn't want to leave it in there.

 

In the case of my truck's engine... yes. But I also did a lot of other maintenance at almost the same time (all these helped a little, but the PCV Valve replacement stopped the bad idling/stalling problem).
(1)Changed the oil and oil filter.
(2)Changed the air filter and Crankcase vent filter
(3)Changed the PCV valve ***

and I'm planning on changing all 8 spark plugs when it stops raining.

BTW I didn't see a screen in the Valve Cover, although I didn't pull that rubber grommet out. It may have a screen with it. I suppose you could take a look with an inspection mirror and flashlight.

 

I also replaced the plugs and wires, and all the filters, including the fuel filter. Which brings up a new problem on my truck-- I haven't replaced the fuel filter in about a year (maybe two--I forget) but it had definitely been in there for years before that. I can't believe it wasn't totally clogged. That said, I've been towing a big old boat around to the tune of about 8000 miles in the past year, and just got back from a 2000 mile trip and parked the truck.

Yesterday, I fired it up after a couple weeks of letting it sit, and drove into town. Coming back on the freeway, it started missing really badly, and was almost cutting out. I managed to get home ok, but I'm planning on heading up to the hills again this weekend (with a slide in camper on it). It seems like it's fuel starved, so I rolled underneath it and whacked the fuel filter a couple times. It now will rev up to high RPMs without missing at all, but I haven't tried it under load. So, what I'm wondering is do you folks think the fuel filter is bad? I'll change it out tomorrow, but before I go to the parts store, I'd like to see what else I may need.

 

Does synthetic oil make good hair gel?

 

try it and let us know.

 

Just purchased a 92 F150 4.9l EFI with about 122,000 miles on it. Was checking things out and noticed a good bit of oil in the air cleaner box. There is a breather cap right behind the oil filler at the front end of the rocker-arm cover. A hose runs from here to a small (was oil soaked) filter in the air cleaner box. The actual PCV valve is at the rear of the rocker-arm cover - behind the intake manifold and difficult to see.

The old one was rather dirty and appeared to be almost clogged up. I just replaced it so I am curious to see if the oil output into the air cleaner is reduced. The engine has also been putting oil out the rear seal. Maybe this will reduce it.

Does anyone know if there is some sort of screen under the PCV on a 4.9l?

Thanks

 

bump

I-cant-find-it.

I swear that if I have to replace that thing I will relocate it.

 

Talk about back from the grave!!!!!!

This one is over 6 years old.......

 

Proper terminology for digging up an old thread is a "Necropost".

My youngest daughter taught me that!

Ray