Hello and many greetings from Germany.

I just bought a 2000 Lincoln Navigator, 5.4 DOHC 32V. Sometimes the check-engine shows me the following codes

- p0171
- p0174
- p0401

I read a lot the last weeks and i know, that the dpfe-sensor couldn´t work correctly and maybe there is a vacuum leak behind the upper intake manifold in the ´elbow´.

a) I can´t reach the elbow, i can´t see anything because all is so deep behind the engine. How does a mechanic may change the egr-valve f.e....how can i rach this area? I am sure i can hear a whizzling sound behind the upper intake manifold...but this one is so high that i can´t see it. the manifold is much higher than the one of my 97 5.4 Expedition. Can i easily remove the upper manifold to take a look?

b) there is another vacuum hose near the battery. from there one hose goes down to a vacuum body, one goes down to the differential (?) an the end of the black hose goes in the direction to the manifold, but its end is open. Is that how it should be? Or has this one must be connected with another hose?

I hope it was not too complicated and my englisch is acceptable!;-)

Does anyone has a diagramm of the engine or the vacuum system?

Thanks a lot and all the best for 2014,

Markus

 

You should just be able to reach back around. Its back there, but accessible...you may have t lay across the engine to get there but its doable. The PCV elbow at the intake is typically the problem especially if you can hear it.

 

I think on the navigator intech has it ontop of the engine right under the Lincoln cover, but I could be wrong, but that's the only one that went bad on mines

 

I think that one runs to the Purge Valve.

Should be the same, its the same engine.

 

On the 32-valve Intech engine (aka, Hot Rod Lincoln ) the elbow is on the passenger side of the intake manifold. (It has two very small coolant lines attached to it to help preheat the vacuum until the engine gets up to operating temp.)

The elbow is connected to a vacuum "T". One side of the "T" is connected to the PCV valve (located at the front of the passenger side cam cover) while the other side of the "T" goes "ontop of the engine right under the Lincoln cover", where it supplies vacuum to the IMTV (Intake Manifold Tuning Valve).

When the 32-valver wants to exceed ~3000rpm the PCM electrically opens the vacuum port within the IMTV and uses the vacuum to rotate the vane within the IMTV to "tune" (i.e, shorten the intake runner length) for high rpm power as opposed to the longer runner length for lower rpm torque. (That why its the Hot Rod Lincoln )

As for the P0401 you want to check that the DPFE hoses are fully connected and not installed in reverse. If they are correctly installed check to see that the EGR valve can stall, or nearly stall the engine at idle when you manually open the valve. If it can't nearly stall it the egr ports in the manifold may be plugged.

As far as the P0171/P0174, if you can hear a vacuum leak your gonna have to find it. Try getting a 3 foot piece of 1/2" clear tubing and hold it up to your ear as you move it around the engine to zero in on the sound.

Good Luck and have a Happy New Year

 

...or find a shop that has a smoke machine.

 

Wow, what a great feedback. Thanks so much! I'll give it another try on thursday. Does anybody has a picture of that area. My workshop manual has just been shipped, that may take two weeks.

Anybody an idea concerning problem b?

Markus

 

Problem solved... I hope...

From the pcv there goes a hose behind the wall. There is a T. From there one hose goes deeper to the engine in direction of the back of the car. The other hose from the t was missing. There was the vacuum leak.

I connected this open end with the open hose (problem b) near the battery. It fits. The rpm came down from 1100 to 800.

I'll take a look at the engine service light next days.

Thank you so far. It's not easy to get help for such a car in germany!

---- OK...20km driven. Again the codes!;-) i´ll check the dpfe next!

------- Now found, that the elbow isnt´t the original one . its´s just a piece of rubber and because of the vacuum ist is squeezed together...will take a look for an harder one.

 

I'm new and would like to join in this discussion. My 04 Eddie Bauer Expedition 5.4 started idling rough and stopping at red lights. Service engine light came on. My son looked up on forums and suggested the idle air control valve. While looking at the IAC, I noticed a rubber hose broken almost in half. It is connected to the manifold with small coolant lines teed into it(ie,pdqford) It is actually an adapter connected to a hard grey plastic tube about 3 inches long, with a rubber 90 attached to the other end. This rubber 90 is attached to a plastic Y that I did not trace. All of this is located on the passenger side almost under the cowling. I had to lay on top of the engine to reach it. I had to slice the 90 to remove it from the plastic Y. Tried pulling and twisting and feared breaking the Y. I repaired them with industrial garden hose, rubber tape, and HVAC tape and replaced them on the vehicle. Problem solved. I removed the negative battery cable for 5 minutes to clear the service engine light(it worked). Have driven for 2 weeks with no problems. I want to replace my "fixed" hose with an OEM part, but cannot find anything that looks like what I have. Any ideas what the part/hose is called? Pdqford came the closest to describing the hose, but my car is not a hot rod so I am a little confused.

 

See if this looks like your setup:

http://www.dealerinfolink.com/F85Z6C324EA.JPG

Check with your dealer for your specific MY and engine size. (The basic Ford part# will be 6C324.)

Your engine is probably the SOHC 2-valve 5.4L engine, quite different from the DOHC 32-valver 5.4L Lincoln Navigator engine that the original poster was refering to. (Ford used versions of this DOHC 32-valve InTech engine in the Mustang SVT Cobra R, the Ford GT, and the Shelby GT500 - thus my refering to it as the "Hot Rod Lincoln" engine - sorry for causing any confusion.)

 

Pdqford, I think I will take your advice and go to the dealer parts dept and point out the hose I need. I could not find any schematic or exploded view of my engine's vacuum hoses. I don't know why this is. I will post a photo when I figure out how.

 

Yes, got the same problem...there are no exploded views of the complete vacuum hoses...

i hope that they are part of the manual i´ve ordered so i can check if the connections are right.

 

Pdqford, you are correct. I pulled the car out in the sun and there on the hose way in the back is a sticker with a part #!! 6C324 . It appears they have made a design change, because mine is not exactly like the picture. Thank you, sir. I failed to mention that my truck(actually wife's truck)is an Eddie Bauer edition. The third hose that you mention ties into the manifold just as you described on the Lincoln Navigator, and that's the rubber hose that was broken. Could we actually have a "hot rod" and not even know it?

 

The vehicles mentioned by the previous post and some 2001-2002 Lincoln Navigator's have the "Hot Rod". The earlier 5.4's had single cam 2valves per cylinder. In 2003 Ford started using the 3 valve per cylinder which is probably what you have in your Eddie Bauer. In the Navigator's that have the "Hot Rod" 32v engine are in identifiable by the 7th digit in the VIN is a R