Boy do I fell like an A$$ for asking this but where is the PCV Valve on a 1999 4.6L?

I am getting a P1131 code which, among other things, the manual says to check the PCV valve. Well I pulled the air cleaner and rest of the fat tubes and there is a little oil in one fat tube. There is a skinny tube off that, going to the driver's side valve cover but there is no valve in that line.

The shop manual seems to show a tube coming from the valve cover on the passenger side and going to a metal tube below and to the right of the air intake. I can't see anything coming off the passenger valve cover except the oil fill tube.

Somebody show me how dumb I am.

Thanks

Pete

 

Oh , Alright -

 

I can't find anything that looks like your pictures.

Are they pictures of a 4.6L? If they are, are they a van?

Could it be that a 4.6L van has the PCV valve located somewhere else?

Or what else could I be doing wrong?

Thanks

Pete

 

P1131/P1151 codes are usually due to a weak or lazy O2 sensor.

I'd recommend replacing the upstream sensor on the passenger side.

Steve

 

I am anticipating doing that. You say "up stream". I could see only two, one for each bank of cylinders. Are they the "up stream" ones?

I was also trying to decide which one is #1 HO2S. I guess you answered that. Passenger side. The parts store says replace in pairs. Is that really necessary?

Also, I still would like to replace the PCV valve; this thing has 110k miles on it, it deserves a new one.

Thanks

Pete

 

Mann, get a Haynes or Chiltons book - They sell them everywhere..

I haven't seen a V8 in your model year have the PVC located anywhere else - I just looked on my DVD and it shows both engines same spot - the have the same heads..

 

"Upstream" refers to the sensor closest to the engine, downstream refers to the ones downstream of the cat converter. Your engine has two of each. Replacement of the upstream sensors in pairs isn't always a bad idea if you don't have the capability to analyze the performance of each one. Downstream sensors rarely fail.

As for the PCV valve, pick up a replacement hose with valve from the Ford dealer. Aftermarket PCV valves can cause some strange problems.

Steve

 

jbrew

I know you are right. You have to be. I just feel like I have my head up my a$$ on this.
I actually have the shop manual on CD. Supposedly the same one the dealers use.

Here are two images from that "manual".

Well forget that, when I try to add to the gallery I get "An Unusual Error Has Occurred"

Anyway, the PCV image for the 4.6L shows it in one location, they don't have an image for the 5.4L. They have one that is titled, "PCV Valve--6.8L Shown; 5.4L Similar".

I bet it is a typo and they should have put the "5.4L Similar" with the 4.6L.

Anyway the 4.6L image shows the tube going to the front of the engine. Now I'm starting to think they mean the back. I'll have to get my head out of where I have it and get it under the hood.

Thanks

Pete

 

The manual I have makes a big deal out of checking for moisture in the connectors. I did and actually found what might be a little corrosion on the pins (identical pin on both connectors--driver's and passenger's side).

I cleaned them and, when I get a new PCV installed I'll do a little test driving. I bet it will show a P1131 again.

Then I'll get new HO2S and replace the passenger side first. I assume that if I am wrong about which sensor gives the P1131, I can swap the sensors.

Thanks,

Pete

 

I was just showing you where the PCV was since you asked . If you want to keep that code from reoccurring I would handle that this way -

1. Clean the MAF - If you want it fixed , you'll start here.

Heres how - http://www.fordf150.net/howto/clean-...low-sensor.php

Reboot - If you don't see nothing in the 3 or 4 drive cycles that was the prob.

2. Look for vac leaks, especially from the PCV line that runs to the back of the motor and don't say you don't have one - you do.

3. Replace both forward O2's - gettem both at the same time. Don't worry about the two in the back.


You do it like that and I'll bet you that P1131 WON'T come back..Don't forget to reboot after the MAF cleaning..

 

jbrew,

Thanks, I think I'm on my way. I had already cleaned the MAP. I didn't know about the link you gave me but I followed essentially the same procedure. (I still got the P1131 after cleaning.)

I cleaned it as part of the procedure my manual says to follow for P1131. The PCV valve was also part of that procedure. I couldn't find the valve because the image in my manual showed the tube going to the front of the engine (I still can't upload those images). Since I couldn't find it on the front, I was confused. You said it goes to the back. That ought to get me on the right track. I was able to see something buried under a bunch of tubes on the passenger side valve cover. This is a conversion van and the conversion company has added a lot of extra hoses and wiring.

I will also check it for leaks but I bet it is the #1 HO2 sensor. After all, if it was something common to the whole system, wouldn't both sensors show faults? Of course I suppose one could be more sensitive than the other.

When replacing a HO2S, do you (or Steve) recommend using any anti-seize compound or anything else on the sensor?

Thanks Again Guys,

Pete

 

Steves right , usually is and that code isn't one that usually ends up being the MAF - but it could be , that's why I listed the easiest to check first.

No anti-sieze on those threads - you don't wanna do that.

 

Well, I'd disagree on that anti-seize... the Bosch replacements I usually use come from the factory with the anti-seize already applied.

I can't think of any good reason to NOT use it. Perhaps you're thinking of the spark plugs...

Just make certain it stays on the threads and doesn't end up on the sensor element.

Steve

 

My O2's came loose all the time with anti-sieze - passenger side especially..

Maybe it's just a problem I have had . I have to say, I haven't heard of anyone else having it.

I must be lucky.

 

Just a final (I hope) update. I went ahead and replaced the HO2 sensor. It was a Bosch sensor and did have something like anti-seize on it already.

I have driven about 50 miles without any DTCs either actual or "Pending" as reported by my scantool. That is about 5 times as far as I could without a P1131 before.

I never changed the PCV valve. I finally found it and when I saw all the crapping around I would have to do to get it out I decided to see if the HO2 swap solved the problem. I think the shop manual recommends changing the PCV before the HO2 because the PCV is 1/10 the price. In my case, it is also 10 times the effort. And less likly to be the problem (I hope).

Thanks jbrew and Steve.

Pete