Now, many people suggest not replacing the valve cover. I chose to replace it as recommended. It was pricey... about $60.00 for it alone. It is up to you of course, but I recommend replacing it, if you believe you will keep the vehicle.
Take your time and get everything ready before you begin. Here is a list of the tools I used for this repair.
- Various small metric box and open end wrenches
- Various metric regular and deep sockets
- 1/4" ratchet wrench and 2" extension
- Channel-lock pliers
- Flat screwdriver
- Small pick (scratch awl)
- Flashlight
- Shop-Vac
- *Acetone
- *Mineral Spirits
- Rags
DISASSEMBLY
Now, let's get started.
Loosen and detach the negative cable on the battery.
Right click on the image and select option "open image in new web" if the image is not seen full or its very small to see.-----------
Left (front-most) Valve Cover
Here's the first picture. Carefully remove the Positive Crankcase Ventilation (valve) [Yellow Dot] from the valve cover. Also disconnect the other end from the throttle body. Retain this. I had to clean it as it was very oily inside. I rinsed it (the valve and plastic pipe) with mineral spirits.
Right click on the image and select option "open image in new web" if the image is not seen full or its very small to see.-----------
Oil Seep Hole Inspection
After the PVC valve has been removed. Look down inside the hole at the five o'clock position. You will likely need to use a flashlight. You can just barely see the edge of the hole peeking out in this picture. If there is a 1/8" hole in there like the one shown in this "staged" photo. You should replace the valve cover. This hole is part of the culprit that lead to needing this repair. Please note that that new valve cover does not have the hole - I faked this image for demonstration purposes.
Right click on the image and select option "open image in new web" if the image is not seen full or its very small to see.-----------Notice the blue arrow. I removed the retaining bolt that holds the dip stick tube in place. Do not remove the dip stick tube, but you can remove the dip stick to get it out of the way if you'd like. Without doing so, I could not remove the spark plug harness clamp that is immediately behind the oil dip stick. Without removing the harness the valve cover bolt below the harness could not be loosened and removed.
Remove the left-bank spark plug wires that are just below the valve cover we will be removing. Give them a twist and then pull toward the front and driver's side of the van to get them off.
Remove all the bolts [Red Dots]. Most will not come all the way out but the one in the lower right corner of the image does. As a matter of fact, the new valve cover does not come with this bolt. You will need it when you put the new cover on - keep it handy for use later.
Right click on the image and select option "open image in new web" if the image is not seen full or its very small to see.-----------I found it easier to work on this repair with the air cleaner out of the way. Loosen the two screws shown here [Red Lines]. Once, loose carefully remove the rubber tube.
Right click on the image and select option "open image in new web" if the image is not seen full or its very small to see.-----------Now prepare to remove the Air Cleaner and *MAF sensor tube. Before you do this you will have to disconnect at least one connector. On my Windstar this connector was placed between the rubber tube (removed above) and the battery. I indicate it with the [Yellow Dot] here. Do not yank on this connector to disconnect it. There is a little tab to depress near the left side. Once depressed the connector separates easily. If yours isn't coming apart you may not have the tab depressed far enough. Once the connector is apart, pull the part that leads to the MAF from its mount.
While the Air Cleaner and MAF Tube should come out as one unit it is easier to remove the halves of the air cleaner assembly separately. To do this, release the clasp [Red Dot] and separate the MAF from the Air Cleaner [Blue Dots]. The MAF tube is the one on the left. Air Cleaner is on the right. Check the filter. Replace it if necessary. Remove the Air Cleaner housing by carefully wiggling it back and forth while pulling straight up. Two rubber mounts as well as the snorkel hold it in place. You should find that it comes out easily.
Other Sensor Wires
In this picture two more connectors have been identified [Red Dots] to the left. These come apart easily too... if you press the little tab - normally on the male part of the connector. The [Red Dot] on the right is the MAF sensor connector discussed previously.
Throttle Control Cables
Next you will have to remove the throttle and cruise control cables. This is a cinch. First remove the bolts that hold them where they are supposed to be. The top bolt [Red Dot] is pretty easy to get to. The other one [Red Arrow] was a bit more difficult. Patience! After the bolts are removed detach the cables.
Throttle Cable Attachments
This picture was taken from behind the engine. The throttle cable with the plastic sleeve [Blue Dot] detaches by snapping it to the right in the picture, then it can be pulled out toward the firewall. The other one [Red Dot] can not be easily removed until the two bolts in the step above are removed. One of those bolts are shown here too at the [Yellow Dot]. The lower cable is attached around the throttle mechanism and in a slot. If you have ever messed around with a bicycle's hand brakes you will see a direct similarity with this fixture. It will come apart and go back together easily. Once you have the fasteners (bolts) removed, and the cables loose, position this part out of the way. {The throttle cable removal steps has been corrected).
Vacuum Lines
Now let's get to the good parts. Here's another picture from the back side of the engine. This one is looking from the driver's side towards the passenger side. The camera was just to the left of the brake master cylinder. Here, I have pointed out several vacuum lines that will have to come loose. Heat had temporarily fused mine on! You will find it much easier to remove these lines if you push them on further first, then wiggle them loose. Each has been denoted with a [Red Dot]. Take note that the large vacuum line [Yellow Dot] is held in place with a clamp. Use pliers to loosen the clamp and move it back about two inches from the end of the hose. Remove only one end of the hose. They will not be a problem and will generally stay out of the way.
You may find it much easier to remove the vacuum lines from the plenum after the top half is removed.
Intake Plenum
First, the little stuff. Disconnect the little vacuum line shown here [Yellow Dots]. Push the connectors on, then pull them off. This helps break them loose. Now... the TSB said replace this. Mine was fine. No oil contamination at all. I replaced it anyway since I had already purchased the part. But like I said above... check yours before you buy the new one. You may not need to replace it.
*I didn't remove the cowling when I did this work, but many people who have found this web document recommend it.
*If you want to remove the cowling here's the procedure for doing this. The cowling which prevents easy removal of the plenum lid contains the windshield wiper motor and linkage to the arm pivots. Be careful prying on this as it can damage the wiper linkage.
It was easy to remove this with the following steps:
- Remove the wiper arms (lift pivot cover, remove 15mm nuts, pry arms up off pivot shafts)
- Remove four phillip screws along base of splash shield. Locate windshield washer tube elbow under far left side of shield and disconnect. Lift shield along windshield line and pop apart plastic connectors (six total). Lift and remove shield. Remove cabin air filter.
- Remove the 8mm bolts from the cowling (two short ones on each side, eight in the middle around the drain and cabin air filter. Remove hood switch (11mm nut right side). Disconnect wire harness from wiper motor housing (right side, two swizzle plugs). Lift cowling up and to the left to clear the wiper linkages from the sheet metal, locate and disconnect wiper motor electrical connector under the back right side of the cowling. It can be lifted out and placed aside.
Next, remove the 14 bolts [Red Lines] on the plenum. Keep track of which one goes where. This is important because they are different. These come out pretty easy; however, the ones furthest from you will take a bit more time for obvious reasons. Keep all these bolts. The plenum is in two parts. The top and bottom. Inside is a baffle (or air conduits that guides air down into the intake. Be careful with all these parts. You should not have to pry on any of them. Once I removed the 14 bolts, the top part of the plenum was loose without any force or pressure exerted. Problem was... I could not get it off the damn engine! The cowling [Blue Line] was about 1/2" too low, or the engine was 1/2" inch too high. In any event I had to get my son to carefully pry up on the cowling. I used a 2" wide piece of pine and only pried up enough to get the plenum off the engine. Note the sensor body near the [Green Arrows]. I use it as a fulcrum. Be careful not to pry against the shiny looking dome on it [Blue Dot]... pry to the left of that - on the body of the fixture.
Intake Plenum Gasket
Once you remove the plenum you will find that there are two parts. One, the baffle which snaps into; two, the plenum. Clean these parts with mineral spirits. Mine where way grody inside. Also, check the [Red Line] in this picture. This represents the plenum gasket. It is one long gasket that goes all the way around the plenum. I carefully removed this and retained it. The recommended parts list from the TSB did not include this gasket so don't break it. When I put the engine back together I found that this gasket had magically grown. It was about 1/2" too long in its circumference. I kept messing with it until it got it to stay put.
Plenum w/ Top-half Removed (Internal baffle not shown)
The culprets of the P0171 and 174 codes... bolts with black shoulders [Red Rings]. Evidently Ford saw fit to put parts in the engine that cannot take oil. The black-shouldered bolts are problematic it this regard. These are the Isolator Bolts. In any event, remove each one. They come out easily. There should be eight of them. Once they are out. Remove the lower part of the plenum chamber. Flip it over. You will find six small circular gaskets. Remove these and toss them in the trash. They will be replaced.
EGR Ports Exposed
Peer down onto the top of the engine. You will see some gadgets that look like butterfly valves. Forget them. To the front of the engine you will see a hole that goes down. Don't drop anything in there. Keep looking around and you will see six nickel-size things that stick up towards you [Red Rings]. Each has a little hole in the center. On my car these (the holes) are about 1/8" in diameter. These are the Exhaust Gas Recirculation (EGR) metering holes. These should be cleaned. This is where the shop-vac and pick come in. Fire up the vacuum and while placing the nozzle near each of these little orifices clean them up.
Super Close-up of EGR Port
This is really nice close-up of the EGR port. Notice the crud built up around the port's oriface [Red Arrow]. That stuff get's cleaned out.
Here's some more information. Before you begin putting the top of the engine back together make sure you clean the intake manifold to intake plenum mating surfaces. This is the area where the six rubber gaskets go. I used a little acetone on these surfaces to cut through the built-up residue that was there. Using a razor with a very low angle of approach these surfaces cleaned up great. Be very careful with the razor. You will be working on aluminum and it scratches REALLY easy. Also, keep the vacuum near by and in use during this careful cleaning process. The vacuum sucks up debris before it has a chance to fall down into the intake ports.
Nicely Cleaned Intake Ports Faces
When you are ready, begin reassembly. This is basically a reverse order of everything discussed herein.
