Yes I agree that the lowers should of been replaced, but unless there is a major leak from the intake gaskets and they have totally failed they will not cause this. I have never seen intake gaskets that cause lean codes cause a rough and stumble upon startup ever. How many windstars are out there with vac leaks from faulty isolator bolts, clamshells gaskets and upper intake gaskets they all have the lean codes but they are never brought in to be fixed because they run fine cold or hot BECAUSE leaky intake gasket fail only to a certain limits since they are still bolted down. Now a hole in the intake or intake snorkel or large vac line would cause this as the leak is large and constant. Anything is possible but after 9 years of ford driveability day in day out I would not be looking at intake gaskets for a car that revs to 2-3k rpms or I wouldn't have a job anymore. As I said I am not there to diagnose and anything is possible but I would think after all these years of dealing with new and old vehicles coming in the shop along with the temp extreme changes we experience in the Midwest I should of seen this by now is all. All we can do is test and make sure.

 

Then you have simply been overlooking them. As I stated before, this condition is particular to the 3.0 4V in the Escape and Taurus platforms and the symptoms fit exactly to what the OP has stated. Argue all you want but the fact that you haven't recognized this situation doesn't make it impossible. At the same time, we are both only working off the info the OP has given us and I have given my best evaluation of the situation. If this were a family members car, the first thing I would do is replace the lower intake gaskets and reevaluate. As I said before, I believe the high idle is a separate issue.

And since you mentioned your 9 years of experience, I will mention that I have a degree in Automotive Technology, minored in Mechanical Engineering, graduated the Ford ASSET Program, and have worked as a driveability tech for one of North Americas largest Ford dealerships (we're currently #4 in sales) for the past 20 years as of last month, although I've worked in the automotive field since 1987.

What does all that mean? Well, it doesn't mean Jack, and it doesn't make me automatically right. I've actually been wrong before, but I've learned from it and it has made me a better Tech.

But one thing I have learned is not to live with blinders on and to listen to others when they share their experiences.

So my vote is, once again, for the OP to consider replacing the lower intake gaskets before continuing the "throw the dart at the mystery part" contest.


Jay

 

I did say anything was possible see quote. Anyway all I am saying is for how many years of working on Fords and all the stuff I have seen and all the common issues I can pick out on each vehicle you would have thought I would have seen the issue you are talking about, even the other Ford guy in the shop has never had a lower intake off on one of these unless we are pulling the heads. Also I have never seen lean codes on these ever unless it is an external leak, pcv hose etc. I am just saying is all. It's really hard to tell without being there. I bet either one of us would figure it out in 5 min if we were there in person to help him.

 

Is anyone here saying that a vacuum leak can't cause a high idle?

 

A vacuum leak can cause a high idle but it has to be large enough. When they are small as in a intake seal leak that has fatigued over time no. If they are large enough the pcm will try to compensate with the iac and rev up and down high rpms 2-3k. Or if the vacuum leak is large but at the point the pcm can still control the engine as in Taurus junction block leaks it will run high rpm 1200 or so you pull iac and it will still run because it has enough air inlet to sustain engine idle. When you pull that iac connector it should die like you turned the key off.

 

Different vehicle but I had a '97 Ranger Splash 4x4 4.0 V6 that was getting lean codes with a slightly increased idle speed. As time went on it increased more and more. At the end when I found the gasket under the fuel rail to be cracked and sucked partially into the front port, it was idling at 1500rpm. Luckily it was a manual 5-speed and bit easier to handle the high idle speed. IIRC, I was getting a IAC code at times also.

 

Yes you will get iac codes because the pcm cannot control the idle by bringing the duty cycle of the iac down far enough to correct it. It's beyond it's limits, kind of like fuel trims beyond the limits it sets a code too when there is a vac leak.

 

It was like once or maybe twice over a long period of time. I did a bunch of other time wasting things before the problem was found which may have been two months as it got worse and worse.

 

Hi again guys.. thanks for your suggestions. This weekend I cleaned the MAF, it looked pretty clean anyway but I sprayed it down good with electronics cleaner. Unfortunately it didn't make much of a difference. I tried to replace the TPS, but ended up stripping the bottom screw before getting it off Anyway, I made a video of the engine and had a couple of questions that I asked in the video, here.
I also made one of me spraying carb cleaner in the cold engine. It seemed to react when I sprayed around the IAC, throttle body AND the intake manifold, but then again it was all in the same area so I cant really tell which one is leaking. Its here
Can you guys tell me what you think?

 

Hi again guys.. thanks for your suggestions. This weekend I cleaned the MAF, it looked pretty clean anyway but I sprayed it down good with electronics cleaner. Unfortunately it didn't make much of a difference. I tried to replace the TPS, but ended up stripping the bottom screw before getting it off Anyway, I made a video of the engine and had a couple of questions that I asked in the video, here.
I also made one of me spraying carb cleaner in the cold engine. It seemed to react when I sprayed around the IAC, throttle body AND the intake manifold, but then again it was all in the same area so I cant really tell which one is leaking. Its here [YouTube] [/YouTube]

Can you guys tell me what you think?

 

First video the hose that is not attached to anything by throttle body is the trans vent hose and is perfectly fine, as for the wires by the intake- tape them but otherwise look ok, hose not attached to anything by egr is ptu vent, you have 4wd right?

 

As for second video you definitely have a intake vac leak but not from old seals it's a large vac leak like a seal partially came out. The spray reacting on both sides is definitely a intake vac leak. If you could stick the straw down in there you could spray directly at lower intake seal just a bit and see if it reacts. When pulling the intake replace all seals including iac and take a hard look at that pcv and pcv hose once the intake is outta the way. Either way you are going to have to pull the intake. Super easy to do, save yourself some money do it yourself.

 

I just realized I double posted, sorry!

Is it safe to assume my IAC is working properly since the engine immediately dies if I disconnect it?

So you are suggesting I pull the intake and replace both the upper and lower gaskets, as well as the IAC gasket? I have found some scattered information on how to do it, but does anyone have a video link to the "how to" for this? I would rather try and do it myself if I can find a good video that shows how, but how much wud u estimate it would cost in labor for a mechanic (not the stealership) to do?

Also, where exactly is the PCV valve? I can trace one of the main hoses coming off the intake as it goes right, then under the IAC and goes into the side of the engine. is that it? It feels wobbly..

 

How to Replace Spark Plugs on A V-6 Ford Escape .: Articles the pvc is on driver side under throttle linkage

 

Thanks for the informative link, but it doesnt seem to include how to get to the lower intake, just the upper.

Is it possible to do any kind of effective check of the PCV connection/seal without taking all that apart?