Tune up '96 XLT 5.0 just under 100000 miles 2 wd

[GeorgeR]

Hey Joe, Thanks for the info. I can feel a couple of cracks in the hose, but so far I haven't seen them. It rained quite a lot today, and I'm hoping that tomorrow I can get under the hood and see what's what. I'm going to remove the existing hose in any event since I have plenty of new hose. I can't remember for sure at the moment, but I seem to remember reading something that indicated that the egr didn't do much at higher rpms, that it's primary function was at lower revs. Does that make sense????
My egr doesn't look much like the one in the picture on the website that you provided for me but the sensor looks similar. The egr does look like it may function the same, maybe just a different model year or etc. The new one that I have looks like the one on my truck tho, so I guess that's what counts. I'm going to put a hose on in place of the old one and pull an oral vacuum and see if it holds. If it does then if the engine doesn't smooth out with a new hose I will try to replace the sensor, and then if I have to, the egr, as soon as I can find gaskets for the throttle body. At least that is my plan of attack, if it doesn't rain me out again.

 

[rizzjc]

Well, good luck.

I'm not sure that what you say makes sense. I thought it was the other way around. I'm not expert, but I've been through this, so thought I'd share. I'm pretty sure that the EGR is CLOSED when the car is warming up, and I THOUGHT wide up at full throttle.

 

[GeorgeR]

Well, It seems that you are right, and I'm glad that you are sharing your experience with me.
My brain seems to only function properly about half the time, and I've learned over the past few years not to take any serious action on anything technical especially until I've had the opportunity to bounce it around a bit.
As I understand the process, as you said, when the engine is idling, the egr is closed: no vacuum. Which also means that when the engine is off; no vacuum. In order to test the egr, if I have it straight now, when I suck on the hose, it won't allow any air to pass thru the egr when the engine is off. Does that make sense to you? I have tested this theory with the new egr and sensor and it's like sucking on a plugged straw, which is as it should be with the egr closed? In any event, tomorrow, weather permitting, I will hook up a vacuum hose to the existing egr and suck on it. If I get air passing through the new hose, then I will assume that the egr is not seating properly in the closed position, and I will replace it along with the sensor. If it doesn't pass air, I am going to replace the hose and see what happens to the codes and engine performance etc. If nothing changes, then I will try to change the sensor without pulling the egr. If that fails, and as you said, it may, I will tear down the throttle body and change the egr and the sensor.
My apologies if I sound confused, it's only because I am, but the more I talk about it the more clear it becomes to me, especially with your input, which is extremely helpful. Again many thanks.

 

[rizzjc]

I still don't think you are quite right. The egr has a diaphragm in it. When you put vacuum on the egr it causes it to open - the vacuum is placed on the diaphragm, which moves the "pin" (I know there's another word for it, but I'm at a loss). The opening of the egr moves a plate which causes the metal rod on the sensor to get pushed up (notice the spring action of the rod on the sensor). That deflection of the rod is translated to a voltage by the sensor, and reported back to the computer. Take vacuum off the EGR, and pressure on the diaphragm is released, so the "pin" seats and the EGR is closed. This "pin" is the thing that apparently just doesn't seat well after miles of buildup, and causes what is really a false reading on the sensor. I suppose you could argue that it *is* leaking, but I doubt it would make much real different. The issue is that the computer, I believe, makes some adjustments based on that false reading, and that could cause some rough idle, and bad gas mileage (I noticed bad gas mileage - I think it was the computer, not the "open" egr causing this).

You can pick up an actual vacuum pump at the auto parts store, for pretty cheap. Might be easier. Or maybe it depends on how much you suck.

Here is a photo of my EGR, right in the middle of the photo. Sorry, kinda blury.

The redish part is the diaphragm. You should see that on yours. My early '97 should look the same as your '96.

And here is the EGR and sensor. Notice the "pin" at the bottom of the EGR in the photo. That's what closes off the flow.

 

[GeorgeR]

Hey Joe, In case you are still listening, I replaced the vacuum line to the egr today. The old one crumbled when I tried to remove it. The truck ran better for a while after I cleared the codes, but then threw the egr code again. I'm going to try to change the sensor tomorrow and if that don't do it, then I'm going to change the egr. I don't know what I'm going to do for gaskets for the throttle body if I need them. No one around here has them. Somehow I don't think RTV or permatex are viable options for this application. Oh well, I learn a little more about it every time I look at it so I guess I'll get there soon.
Thanks again, George

 

[GeorgeR]

BTW, in the first pic, immediately to the left of the egr, there is a black knob with long notches in it, What is that doodad for? In my engine bay it sets to the left and above the egr and seems to be connected to the vacuum line to egr through a plastic fitting that is underneath it. For sure the vacuum line goes from the egr to that platic thing, but I wouldn't swear yet that they are connected.

 

[rizzjc]

I think that's called the EVP, and I think that's what controls vacuum on the EGR. The computer tells it to open the EGR.

You're gonna need some gaskets, and a couple cans of throttle body cleaner. Might as well shine everything up while you've got it apart. Also, be careful if you use gasket remover - that stuff takes the paint right off the metal! Some auto parts store around you should have the gaskets, or certainly any Ford dealer. I would think that RTV would work - it's only air going through there, but it would be a pain to deal with, so better to find the gaskets. I can't remember if I had to go to Ford for them, but they are only a few dollars.

Surprises me that the hose crumbled. Mine is still fine, nice and plyable, and I reused it.

 

[GeorgeR]

Yep, well I ordered the gaskets onlline from Advance, but they won't be here until next week. So I guess I'll have a conference with Jack Daniels and relax until they get here. You are right, RTV is a pain in most cases, but can be a lifesaver sometimes. I would rather use the right parts than get in a rush and screw something up.
After re-evaluating removal of the sensor and cutting my hand up, I think I am going to give up on that and just go ahead and tear out the throttle body. I want to see what it looks like anyway. whoever put that transmission dipstick tube where it is should have it shoved up his*** So anyway I guess you win I only beat myself up so much and then. Of course, if I were a contortionist, I could get the sensor off, and probably screw up my back more, just to prove a point. The only way I can figure to get the damned thing (connector) off without breaking something is to remove the sensor. Is there a special tool available to open the latches of that type of connector??? It looks to me that if you remove the connector, then you can have reasonable access to the screws that hold the sensor on.

 

[rizzjc]

I think that you could use a screwdriver to unlatch the connector. I broke mine, 'cause I couldn't see it. It's fine, just doesn't latch anymore. Oh well.

I honestly can't remember why I couldn't get anything off without removing the throttle body and elbow, but I couldn't. Like I said, good upportunity to clean all the gunk off it.

 

[GeorgeR]

For sure, and like I said I want to see what it looks like inside the TB. Did you say that you experienced a significant improvement in gas mileage??

 

[rizzjc]

I believe that my gas mileage went down once the code appeared, and maybe improved somewhat after I finished the job. It did run smoother. There's a lot of buildup in there to clean off.

 

[GeorgeR]

Hi Joe, Ok, I've got the gaskets supposed to be here first thing in the morning and if it looks like the weather is going to hold I will probably start on this thing then. A couple of questions;

I have a Haynes manual and it says that I should drain the radiator until the coolant is at a lower level than the egr housing. IS this true in your opinion???

#2; The book says that the inside of throttle body is coated inside with some kind of special stuff which helps keep from accumulating gunky build up. Your opinion please if you have the time. Speaking of time, how much time should be involved in this process for a klutz???
Thanks

 

[rizzjc]

I have a Haynes manual and it says that I should drain the radiator until the coolant is at a lower level than the egr housing. IS this true in your opinion???

Umm, I can't imagine why. I didn't.

#2; The book says that the inside of throttle body is coated inside with some kind of special stuff which helps keep from accumulating gunky build up. Your opinion please if you have the time. Speaking of time, how much time should be involved in this process for a klutz???
Thanks

Yeah, everyone says that about the "coating". My opinion? If it's coated with GUNK, then the "coating" isn't doing any good. I just used some foam engine cleaner, and a toothbrush. That cleaned the plate just fine. Beyond the throttle body it REALLY was baked on. Other's have said they had to sand the plate to get the stuff off. Again, I didn't worry about the coating, 'cause it didn't keep stuff from building up, so obviously was worthless.

Time? That's a tough one. You gotta have a lot of little sockets, open end wrenches, etc. If you have some small wratching wrenches, they are GREAT! It could probably be a 2 hour job, but with all of the cleaning and then trying to find just the right tool to remove that one bolt that you just can't get to ... I'd allow a couple days.

Seriously though, those bolts on the elbow are a bear. You need a REALLY small wrench. I managed with a socket, but it was a real pain to actually get the bolt out, 'cause the wratchet backs it out against something else, and then you're stuck there. Anywhere, you'll see when you get there. Just have some small wrenches. It's like a 4mm or something silly like that (at the end of the stud), and you need to get a good bit of torque on the darn thing to break it loose!

 

[rizzjc]

Hey George, did you get this all worked out?

 

[GeorgeR]

'96 Ex 5.0 etc

Hey Joe, No, My Burglar system decided to go berserk all of a sudden so, I've been concentrating on that for the moment. We get a lot of electrical storms here and sometimes it screws up the best laid plans.
I will be getting back to the Explorer sometime in the next couple of weeks. Actually, replacing the disintergrating vacuum hose helped a bunch and the old gal runs somewhat better, so it's not an emergency. I'll let you know as soon as I have something to report. Thanks for asking.

 

[GeorgeR]

Hey Joe, The BA is in my house, not my explorer. That one works ok as far as I know.
I felt what feels like a mounting flange with a small (6 or 8 32) stud under the TB that appears to be for balance going to the intake manifold or block. Did you find something similar on yours??
Thanks George

 

[rizzjc]

Not exactly sure what you mean. I think there are only 4 bolts that hold the TB on, at the 4 corners. I'll look through some of my other "unassembled" photos when I get home and see if any of those help you out.

 

[GeorgeR]

'96 EX etc

Yeah, I'm not sure either, and of course I can't see it. Just thought you might know. I thought that might be why you needed the small wrenches you spoke of? It's a small stud and nut. I'll find out for sure when I get into it.

 

[rizzjc]

Oh, I think I know. There is a bracket bolted to one of the studs on the front on the throttle body, I think. Once out take the nut off, I think you need to get like a 6mm wrench on the stud to remove it. It holds the throttle body to the elbow. You have to do that where the elbow is bolted to the intake as well. Just go slow. It'll all make sense. Remove the cold air intake, then the throttle body, then the elbow. Don't skip any steps, pass go, or expect to collect $100.