Good Day All

I want to replace the PVC valve on my 95 351W (SD) and was advised that I have to pull the plenum to access the valve and gromment that it mounts in. Reason is oil leaking from that grommet.
I am wondering if this is the best way to do it and what gaskets would be involved with this procedure. Also, what else can/should I check and/or replace while I got this piece off? My plan is to replace all the vacuum lines while I have this thing off.
I will also be doing my 163,000 mile oil, lube and filters change, with "the big tune up" (coil, cap, rotor, wires, plugs, timing) the same day. This is a follow up to my new free flow exhaust job.
Any thoughts or direction is always welcome.
Regards
CS45

 

You don't need to pull the plenum for that. Just use a mirror and reach around with your hand. Be sure to check for vacuum at the port that comes off the plenum for the PCV valve - I have found a few plugged with carbon on Windsor motors.

 

Jas88 - thanks for the tip.
Maybe I worded my question wrong as I am going to pull the plenum off to get at all the vacuum lines that wrap around the back of the motor and have a look at the general condition of whatever is back there.
I guess I am asking about the procedure and what, if any gaskets I'm going to need.
Pointers from anyone that has removed a plenum would be appreciated.
Regards
CS45

 

You will need a upper intake gasket set and this will be a good time to clean your Throttle Body and EGR Valve. The gaskets will be included in the set for these items.

Other than disconnecting the throttle and trans cables from the throttle body it will be obvious that all vacuum lines, etc will need to be removed. You will need a #40 torx to remove the bolt in the center of the plenum. There is a special tool for this but I use a 1/4 drive extention with the torx taped to the end to gain access to this bolt. The other bolts are exposed and easy to get to.

Be sure to stuff rags in the lower intake opening(s) to insure that you do not drop anything into them. You will need to clean and scrape all gasket surfaces to insure a good seal when re installing the plenum.

You may want to check the condition of your valve cover gaskets while you have the upper off as they will be easy to replace then.

I am sure that I am leaving out a step or two as it has been a while since I have r&r mine but it is not a hard job. Good Luck!

 

BTW it's "PCV" valve, not "PVC". Stands for Positive Crankcase Ventilation.

x2 on taping the torx socket to your extension when you go to take out the center bolt. I have done this on 2 302s and it's not that hard. All you need is the gasket that goes between the upper (what you called the plenum) and lower intake manifolds.

Also agree you should change the valve cover gasket on the passenger side while you are in there. Use Felpro gaskets.

 

yes use the felpro gaskets but get the rubber ones for the valve covers not cork.


and redlightning is dead on with the dissassemble except ya gotta keep an eye on a ground wire. theres one on the passenger side of the plenum and is hard to see.

 

Recently had the upper intake off of mine off for some chores & would like to add my 2c's. Unless your TB is absolutely hideous, you can leave it on & just clean the outside. Particularly if you're not going to clean the inside of the upper intake. I did however take a grinder bit to the space for the torx bolt so I could get it back in easier & out later without trouble.

The FelPro gasket I used was part# MS94176 for about $7. I cleaned the surfaces with scotchbrite & brake cleaner & used no sealer.

While I had it off I used some pre-bent hose from a goodyear hi-miler kit & the original PCV elbow To relocate the valve to the outside/forward then over the top to the intake, rather than around & behind like stock.



Detail of PCV




Something else not mentioned is the EGR riser tube. Mine cracked in the bellows area while doing other work & since I couldn't "see" it under the cloth insulation, I about pulled my hair out looking for the source of noise.

Concerning the vac lines in the first place:

If they are covered with tube wrap & you're leaving all the vac solenoids in place, I'd just inspect closely & leave them in place Unless they are showing signs of what I call "cross-hatching". Little fracture looking lines on their surface which is a prelude to them literally turning to dust.

(On edit)

With the upper off, its agood time to take care of the disintergrating foil insulation on the AC box. I wiped it clean with a damp cloth, then acetone. Then I took long strips of true aluminum duct tape & started from the bottom and went up, shingle style. It has sealed tight, & stayed on.


.

 

Well, I'm into the job before I planned due to the ruptured pre-bent heater hose coming off some wierd looking and probably dealer only fitting coming off where the thermostat mounts. Have everything off except that special T40 torx bolt. Now that I'm into it I'm wondering if it's not time to "cleanse" the engine bay. The entire air system is looking good.........how much of the stuff actually comes out if I plan to leave the air pump as an idler?

Removed the throttle body and it is BLACK and crispy where the EGR is and where the TB mounts to the plenum. I recently replaced the EGR riser tube and since eliminating that and another exhaust leak at the passenger side manifold, I'm not running anymore CEL's and getting some better milage. Should I change the IAC and TPS since I have everything apart or just give everything a good cleaning?

I have some parts to get and that special torx tool. Once I get that uppere intake/plennum off I will get to see the rest of the engine and get to the valve cover (rubber as advised) gaskets on and the PCV changed out.

CS45

 

Do you mean the bypass hose nipple on the T-housing? If its corroded, you should be able to pic one up pretty easy at a Junkyard or parts store.


When I pulled my stuff off, I took the side pipe assy that comes off the pump (feeding the diverter valves) as well as the cross over from head to head. I used 5/8ths inch dia. bolts (SS) with 11 threads per inch to screw in the air injection passages of the heads where the cross over pipe was. After unbolting the solenoids & capping the vac source that feeds them, I left them connected to the harness but wrapped them in tape and just moved them off the intake, then zip tied them to the fuel line out of sight.

I'd clean the IAC, but leave the TPS alone for now just to keep from introducing another variable into the equation.

 

Hello all.

Here's what I ended up doing:

1. Removed and thoroughly cleaned the black tar-like coating in the throttle body, plenum, EGR, IAC and even the vacumm stem coming off the plenum.
2. Deleted the air inject system piping and related vacuum lines. Left the air pump hooked up and attached the system muffler directly to the pump outlet until I can secure a new shorter belt.
3. Removed, cleaned and replaced valve covers and installed new hi speed valve cover gaskets, just because I was in there. Valve cover gaskets were not leaking and the source of my oil leak was from the grommet where the PCV hooked into the valve cover.
4. Replaced all PCV components with new and re-plumbed the PCV hoses as per example supplied by Scndsin photos above, less the pretty blue hoses. I went with straight black.
5. Replaced ignition wires with 8.8mm black.
6. Replaced cap and rotor.
7. Removed the coolant lines to the throttle body and removed cab heater supply lines. I live in SW Florida, it's plenty hot here.
8. Re-installed everything with new gaskets.

All that work and climbing in and out of the engine compartment over 4 days in 90 plus sweat dripping heat and damned didn't the truck fire up on the first crank.

The coolant system is filled with another load of cleaner so once I have the minimum 3 hours of hot use I will cleanse the coolant system and fill with AF, then fill my tank and see what performance improvements I have gained.

Thank you once again for all the help and support.
Regards
CS45