i wanna check the pcv valve but cant find it anywhere . I searched here and at RPS with no luck . There was conflicting information too . Some people said it can't be replaced others said it can . the haynes manual is useless for a 4.0 SOHC. could someone post a picture?

 

I always seem to find them stuffed in the top of a valve cover.

 

It's on the back face of the driver side valve cover. There is a large PCV hose to the center and a coolant heater tube loop clipped around the outside. You have to release a retainer clip near its base to unscrew it from the valve cover.

 

ok i saw that but wasn't sure if that was it . I didn't want to start pullin on the wrong thing. I can't see how to release it. Whats the magic trick ?

 

The EPA says that manufacturers have to either put a flow monitor on the PCV or they have to install a "positive retention device" to make sure it doesn't just fall off in operation. Most manufactures chose the retention device. Of course, this means that a 2 minute R&R job grows to 20....

I haven't replaced one before and the factory shop manual gives a vague non-explanation.

Your question piqued my curiosity, so I went out and tried it on mine. It was not fun. Here's what I did, right or wrong:

Wait for engine to cool.

Pull the large PCV elbow off the PCV valve

Clamp off the two coolant hoses to the horseshoe tube. I used two needle-nosed Vise Grips.

Squeeze and slide the constant tension clamps up the hoses.

Remove the hoses from the horseshoe tube.

Slide the horseshoe tube off of the PCV valve.

Turn the PCV valve 1/3 turn CCW to release it.

Reassemble in reverse order.

 

I see the clamps , i tried to squezze them with my hands but they wouldn't move at all . should i use channel locks and just squeeze .... also , i only see one tube going to the horseshoe, it comes from a T on the other side of the motor. is it the tube coming into the elbow that also needs to be clamped off ??

so did your pcv valve still rattle,bob ?

it seems so weird that this isn't anywhere to be found on the internet or shop manuals

 

Holy crap why are you having to clamp off and remove coolant hoses for something completely unrelated like the PCV valve? Mine is pressed into a rubber o-ring and is only held in with minimal tension. It's this way on both my 2.5 and 5.0.

 

1) As stated above, EPA changed the rules on PCV monitoring/retention;
2) There is now a small coolant tube wrapped around the PCV valve to act as a heater - it prevents the formation of ice inside the PCV valve.

 

ICE INSIDE THE PCV??? Never heard of that, and I doubt my climate would allow such a coincidence. What year did the EPA make this change? I assume after 2001 or so, huh?

 

I used channel locks to gently rotate the valve back and forth a little until it broke free, then rotated it about 1/3 turn CCW to remove. I couldn't say if that is the "right" way since my manual doesn't really tell you how to remove it.

There are 2 coolant hoses - one to the tee in the heater hose, the other to the PS of the intake manifold.

The elbow just pulls off of the PCV valve. No need to clamp off the PCV tube. Not a good idea anyway since it is plastic, IIRC.

Yes, the PCV rattles but mine is still a low miles truck.

 

Good point, if the PCV doesn't "rattle", it is probably stuck open or closed and in need of replacement. Otherwise, go ahead and replace it anyway, since it's just a couple of bucks.

 

It happens. Obviously, the colder the weather, the more likely it is. I've actually seen the PCV valve ice up, cause a reverse flow through the PCV closure tube and then ice the throttle valve to the point that the plate wouldn't open. If the PCV valve and the PCV closure tube both freeze solid, it blows the dipstick tube out or it can even damage oil seals.

I don't remember the exact year but it was sometime around then.

 

Bob you are a library of information....and I must ask this awfully invasive question to satisfy my curiosity. What do you do for a living? Tell people information all day long!? You amaze me on a daily basis, and your contribution to this forum and its members gets taken for granted all too often.

On a more personal note, I appreciate your commitment to this forum and it's members. You're faithful, reliable, and very knowledgeable. If your wife ever complains of you being on the computer too much, just show her this comment right here and she will (should?) be rest-assured it's worth every keystroke! (I'm assuming you're married, because what woman wouldn't want such a smart fella?

 

I used to work as a powertrain engineer responsible for the development and release of PCM calibrations.