Hi and thanks- I might have a suggestion

[studioman22]

Hello good people and thanks for this great forum. As a new member who has been reading for hours around here trying to find some answers to my specific problem, one thing I have noticed- that trying to find problems/solutions for your specific engine type and year model is very frustrating. While you may find similar problems, either the year model or the engine type is slightly different.

So may I suggest maybe adding a forum that is sorted by specific engine type and year model so that users like me can go there and know that all related posts are concerning my specific year model and specific engine type? I really feel that would speed up this process tremendously.

If there is one, please point me to it! Otherwise, can a moderator please tell me the best place on this site to post the following information/problem?

My situation is this:
I have a 2000 Ford Explorer XLS, Auto, with the 4.0L V6 OHV engine. That much I am sure of, as I have checked the VIN number and all.

So yesterday on the way home from a trip, I noticed the engine running really rough mostly at idle all of a sudden. As long as I keep my foot on the gas, and over 1K on the tach, it won't die, and runs fine at speed on the road. The Check Engine light has been on pretty much since I bought the car used a few months ago. And my mechanic, although he tries, is just not that good with the Ford computer related problems. He has the $300 diagnostic computer, and can see the codes, but has not been able to diagnose the problem correctly, because at this point I believe it is one of those "gremlin" problems not directly related to codes, and more something like a vacuum leak from a hose or something which then causes the computer to display the codes.

So I tried replacing the MAF (Mass Air Flow) sensor after an Autozone guy hooked up his computer, and said that because it was showing lean on both banks, that 90% of the time it is the MAF. Well, it wasn't- no change. Although when disconnected, the engine did idle up a good bit. That typically indicates a bad MAF. So fortunately he gave me a refund, thinking that his part was bad. I had him reconnect his computer to see any new codes with the new MAF on there. At that point, the previous codes were gone, but a new one came up (P0113) indicating a problem with the IAT. CEL still on.

So then, after trying to find vacuum leaks in the system, I noticed that the EGR Pressure Sensor had broken, and on the high side, the nipple was broken off, and the silicone hose attached to it was all messed up on the end, and barely hanging there. So I replaced the sensor with a new one (God, this gets expensive)- and installed a temporary rubber hose with a nice tight fit.

A bit of improvement from that, but not much, and the Autozone guy told me I would need to drive it a while and let the computer recalibrate itself. It was about 10 miles home, and at arrival, still no major improvement. Any ideas?

 

[JDraper]

Welcome to the site!

To 'recalibrate' your computer, disconnect the battery and let it sit for a few minutes. That will clear it back to a default level. It will also clear any codes stored in memory. If you do this and the CEL light comes back on, you still may have issues somewhere else.

Your problem does sound like a vacuum leak, and there is a history of lower intake manifold gaskets leaking on the 4.0 OHV motor. Those gaskets leaking will cause the symptoms you are seeing.

 

[BrooklynBay]

Welcome to this forum! Do you remember the code numbers of the original codes that the mechanic found, but didn't know what they were? Was it P0171 or P0174? If so, then check # 51 in my list of useful threads for more information: http://www.explorerforum.com/forums/showthread.php?t=177975

 

[studioman22]

Welcome to the site!

To 'recalibrate' your computer, disconnect the battery and let it sit for a few minutes. That will clear it back to a default level. It will also clear any codes stored in memory. If you do this and the CEL light comes back on, you still may have issues somewhere else.

Your problem does sound like a vacuum leak, and there is a history of lower intake manifold gaskets leaking on the 4.0 OHV motor. Those gaskets leaking will cause the symptoms you are seeing.

Yup, done that many times already. Still no change. In fact, done after each change. But it is still idling pretty bad, and shutting off sometimes, other times racing up to 2K on tack and then coming back down. And then sometimes it will act like it's recalibrating and remain at idle (about 850). If I didn't have to deal with the computer, otherwise I would say it exhibits typical symptoms of bad spark plug/cables, but the guy at Autozone assured me that if it were, that the codes would come back showing a misfire.

 

[studioman22]

Welcome to this forum! Do you remember the code numbers of the original codes that the mechanic found, but didn't know what they were? Was it P0171 or P0174? If so, then check # 51 in my list of useful threads for more information: http://www.explorerforum.com/forums/showthread.php?t=177975

#51?

What exactly do you mean? Post ID #51 at that link you gave? If so, in that link there is no PID #51? Also, yes, I believe those were the two codes originally. And btw, I had already read that thread. In addition, I just tried again to find more vacuum leaks using that old mechanic's trick of spraying cleaner or WD40 around hoses in and around the intake to catch the engine revving up. And nothing nowhere. Geez, this is frustrating.

 

[BrooklynBay]

Look at the link in my signature that says my list of useful threads.

 

[studioman22]

Look at the link in my signature that says my list of useful threads.

Yes, as I said, I had already read it, but it is for the SOHC engine. Mine is the OHV. Which is exactly the reason I made the suggestion of trying to find a way to sort this out so people can browse by specific engine type and year model. I know I might be asking for the impossible, given there are so many variations. But it might go something like this:

1) Enter your model year
2) Enter your engine type

Site Returns:
3) Following are a list of threads that pertain to your specific vehicle-

 

[Sams01XplrSprt]

welcome studio

 

[BrooklynBay]

One feature that was just recently added to this site is the link under the profile that says vehicle specs. You could see the type of engine that the person making the post has.

 

[studioman22]

welcome studio

Thanks, glad to be around.

Seeing as I bought the special tool needed to remove the MAF, can anyone tell me exactly how to clean it and with what? I see posts referring to cleaning it all over, but can't seem to find one that describes how and what is best to use.

Am going to try and clean IAC and MAF to see if that helps. Also, would not spraying wd40 in and around the intake manifold near the edges also cause the engine to rev up a bit if there were leaks there? In other words, isn't there a way to test the intake manifold for leaks before undertaking that involved job of replacing the gaskets?

 

[BrooklynBay]

Check the links in # 42 of my list of useful threads for more information.

 

[studioman22]

Problem Found

Geez. So after a new Haynes manual, a new set of plugs and wires, a new MAFS, a new fuel filter, a new EGR pressure sensor, new tools to deal with all of that, and cleaning the IAC, the sucka STILL had no change in the idle condition. So I became more determined than ever to find the problem.

I went back to the idea of a vacuum leak, because that seemed most likely after all that. So out came the WD40 again and this time I was extremely thorough. Well, I got lucky and hit a leak spot. Immediate engine rev, and confirmed many times. What a real bad spot for a leak. It turns out there is a gaping hole from some kind of overheating in the upper air intake, right by the flange that fits over the EGR valve pipe that goes into the intake (the big one, about 1" in diameter). And it is underneath, where it cannot be seen, only felt. It appears that the used car dealer I bought it from a few months ago sprayed silicone on it as a temporary fix. And that is no doubt why the CEL has been on since the day after I bought it- because it never really was done right.

So now the question becomes- Is there a way to permanently seal that hole with JB Weld or something? Or am I faced with getting a new upper air intake? I did find one at a junk yard for 75.00, unless someone's got any other ideas. In the meantime I took a piece of hard plastic and epoxy'd it over the hole. When I cranked the car up, it already runs better, but I am sure the computer is recalibrating.

But yeah, with that hole there, no wonder all the error codes and CEL. .

Anyways, thanks for the suggestions folks.

 

[Dannyboy]

as for the search issue, try this

click "search"
click "advanced search"
hilight specific areas in interest of "search forums"
include child forums and you should be good to go, you can search 4.0 running rough in the "95-01" forums.

I typically search "posts" instead of threads as well.