JT-27

Redneck/Redman - did you guys fix your trucks, and if so, what was the issue?

OneRonster

Had the same problem turn out to be that 90 Degree elbrow and the one coming out of PVC to back of intake as well.

Auburnfan400

My '03 4.6 did that exact same thing. Now it brought up different codes than yours, but it reacted the same when idling and yes, there was a hole in the vaccum seal. Simple cheap fix

JT-27

Do you any pictures of the elbow that's leaking? I still couldn't find it on my 4.2.

OneRonster

Take you some starting fluid and spray small amounts on the hoses and you can find they leak that way as well.

Crummy4.2

I've got the same problem on my 1998 4.2, it runs fine, but it just idles rough and kinda shakes like it has a cam. However, I have already changed my 90 degree elbow. I think it just connects the valve cover to the intake plenum to burn the valve leakage and let the pressure out of the valve cover. When mine went out it didn't really hurt anything, it just started hissing.

Crummy4.2

JT, the 90 degree black boot is right under the intake plentum, front and center. The outside of it is about 5/8" diameter, it connects a 1/2" black tube to the bottom of the intake plenum.

JT-27

Thanks bro, I'll check it out tomorrow. I thought I had found it, but it was underneath the throttle body and it was almost impossible just to get a hand on. I feel like a complete moron, but I can't seem to find the PCV valve on this thing either. Time to get a Chilton.

Crummy4.2

JT, the one connected to the bottom of the throttle body is a 90 degree metal elbow with a rubber hose coming off of it. The one with the rubber elbow and plastic tube is in the same location but 2-3 inches closer to the rear of the motor. If you simply pull the intake boot off your throttle body and take the cover that say 4.2 spi off your throttle body, you should be able to get your hands in better. Changing this elbow is as easy as slipping a spark plug boot on and off, you shouldn't need a manual for this operation, but it is always good to have a manual for every vehicle you own.

The PCV valve is located on top of the passengers side valve cover, all the way at the back. To check operation: start the engine and let it idle. Pull the PCV valve out of the rubber grommet on the valve cover. Touch your finger to the end of the valve. If you can feel vacumme, it is functional, if you can't feel vacumme, replace. Come to think of it, I think mine might be shot b/c the valve cover gaskets are starting to leak.

JT-27

Crummy4.2 - I owe you dude, thanks! That description was just what I needed to find it, and guess what - that was my problem. The entire back of that elbow was melted and there was a huge hole in it. Found the replacement at O' Reilly's for $7, and 10 minutes later, my truck was purring like a kitten. I seriously owe you, that was driving me insane, thanks again bro.

Here are a few pictures for those still looking for it.