I read...and lost...the lebgthy post regarding this issue.
Error codes p0172 and 4. Suggesting the PCV elbow has a leak in it.
Popped the hood open, located what i thought to be the PCV on the passenger side over. followed the hose back to behind the throttle body area...it appears to be a very tight squeeze/reach where it reneters the engine. I was barely able to see it and then barely able to get a finger on it and feel around...felt like the outer corner of the elbow was thin as if where some heat may have compromised its integrity.
Is this the right part? Sound right? The elbow turns into a cylindrical switch? that, as i found out the hard way, has another stem coming off it that contains radiator fluid. I removed the stem clamp and pulled the smaller hose off only to have fluid shoot out, so quickly replaced hose.

I guess what I'm wondering is, does it sound like i have found the correct elbow to replace ? If so, I'm curious as to how the heck to get to it enough to replace it? If it just slides off, will it too shoot out radiator fluid?

Any help or pictures would greatly be appreciated. I'm mechanically inclined believe it or not, just not familiar with this procedure.

Thanks!,
Pat

 

You found the right part, theyre somewhat common to leak in the back.
Probably a dealer Item only. Atleast for me it was.
I'm not sure what the 02 looks like but if at the elbow in the back feels thinned out, its probably rotted and leaking.
Some else might chime in about what that code could mean, not to familiar with codes.

I know its tight back there... If its too tight, you can remove the throttle body and elbow (clean it while your at it, along with the egr ports in the elbow, and IAC)

On some models there was a splitter at the throttle body with a few coolant lines going to it, no biggie if you pop one off, just plug it temperarely with a bolt or screw, replace the hose that you need to and plug it back in. You probably just need the boot at the end of the hardline. And maybe the elbow itself.

Not sure what you mean by cylindrical switch..
It should look something like this.


Disregard the circles. But the throttle body on the right might look like yours. They changed them a bit through the years. The tube that looks like its going from the pcv to the back of the throttle body actually attaches to the intake plenum just under the throttle body. I just laid it there to take the picture. The red circled coolant tree is probably where you had coolant come out? Just plug them temperarely.

 

THanks for the input Toyz. After seeing your picture, i went out to look again... my throttle body appears slightly different than yours? The back end of it seems less complicated on my 02' and the elbow in question turns "inline" into the back of the TB. And yes, as you mentioned, the elbow appears to plug into a unit that has a smaller 3/8 fluid line, the one i got squirted by.
So do i just get my fingers back there and push that elbow off? Does it just slide on n off? And should i assume that no fluid will shoot out upon doing so?
Sorry so many question, first timer here.

From what i can tell in the pic , you are not showing the culprit pcv elbow, correct?
Thanks!

 

Yah, its a bit hidden in my pics, under the back of the throttle body. I know they changed a few things around from year to year. In my other pic the throttle body on the right was from a 99 and the one on the left was from a 00. Scroll down here about half way and youll see a better pic of what the back elbow looks like, in jbrew's post.
https://www.f150online.com/forums/v8...ough-idle.html

It's pretty tight back there but it will pull off with some twisting and pulling. Shouldnt be any coolant in that particular line or the elbow in the back.

You have the plastic intake I believe so the back might looks like this where it connects

 

I found JBrews pic last night and saw that. Even though, mine line itself looks much different with about 1 dia. dense insulation foam/rubber on it, the boot pic looks the same.
He also said " I can take a long screw driver and pop that elbow off without removing ANY other parts on the truck. Theres NO clamps, it's a Push on /Push off.- Takes about 5 minutes to yank the PCV system - It's a easy fix!"

So after my 1 hr of investigating this 5 min. fix job....lol and with your and JBrews help, I do believe I got it down. Beats the heck out of going to the dealership and some of the horror $tories I've read here. I just hope it is the culprit and I can clear the codes.
If not, I'll clean the MAF sensor next.

Even my PCV end looks different. I yanked the hose off it, and found it has a flat square flange the hose stops up agaisnt...as if to keep it off the heated engine. And where it does go into the engine, appears to be some kind of locking tabs 180*s from each other holding the PCV in place. I tried with channel locks to turn the PCV and remove from engine but it didn't want to turn at all. Being plastic, I decided to leave it rather than reef on it.

Thanks again for the help, going to try to get back into it today.

 

I know some of them had insulated lines on them. They must have changed them up a bit. Wish I could help more. Sounds a little more complicated than the ones I've seen. Any way to get a picture of what your looking at?

I've found images of what the pcv looks like at the valve cover (square end) but nothing on what the back side looks like.

 

Hows it runnin Toyz ?

 

The new motor? Like a champ. Sooo smooth and quiet (for now) Seems to shift a lot better with the rpm's more stable and I can actually drive it like a truck. Don't have to watch my rpms to stay out of the knocking anymore. Trying to hunt down a vibration around 4500-5k rpm's in the drive train somewhere. Might have been there before hand and didn't know it.

 

You sure it's an engine vibration, not the rear end ? When the fluid breaks down in our rear gears, they tend to vibrate and shake a bit. Like at about 55 mph.

 

Ah.
Nah, felt more like either driveline or rear end. Needs a fluid change anyways. I'll see if it helps. It did seem to be around 45-55 under acceleration. When I let off it would go away but not completely.

 

Yea, the 98 system without the insulation sleeve -



98 sleeved -



98 with bad elbow pics -



Here's a 2000, -user JMC installed a water seperater on his system, pretty cool -

 

Yea, I thought it was the trans when mine did that, it got worse pretty quick. Like you said it went away off throttle. I had to pull off the freeway a few times it would get so bad. I got on this site and inquired about it. Everyone said the rear end fluid. I didn't think so, but I changed it anyway. That was it lol.

The fluids rated for 100,000 miles.