Rough idle, strange shifts, 02 XLT

[billsyzfr-1]

Hello all, and thanks in advance. I am registered in another forum for Cadillacs, and found that these forums are the best of help. What I( have is a 2002 Explorer, 4.0 Auto 4x4. No check engine light, no codes. In between shifts, I get a vibration.... almost a stumble. then when on the road, at any consistant speed it will at times stumble. Give it gas or decrese gas and it comes out of it. The idle is a little rough at both cold and warm temps. I took it to the tranny shop and they said the tranny was fine, probably something in fuel/air mix, they'd seen it in the past. In my area it's 80-100/hr to look into it. Want to try to fix myself before I go that route. Again thanks for any help you may have to offer.

 

[97&67_Stang]

I have the exact same vehicle and similar problem - I too would like to say thanks in advance, and any help would be appreciated. We had been to Ford 3 times. They installed platnium plugs, wires, air filter, new timing chain guides (per a recall), fule filter, and did a genreal check. They said the idle was normal and never noticed anything unusual. We have over 800.00 in repairs so far and still have the probelm. Anyone got the answer?

DCN

 

[Buttsy]

Some recent threads are referencing an "IAC valve" as causing idle problems. Don't think it would cause shifting probs but a rough running engine may seem to shift poorly. The valve reacts according to engine load so it makes sense that gas peddle movement may change the symptoms. Do a search on IAC valve for more info.

 

[Richie_007_1968]

My 03 XLT Expoder is trash

Rough idle? Falter at shift point? Let me explain what I have found.....

Ford has an issue with the transmission called the OD servo bore. The way the transmission operates, it uses the OD servo to engage 2nd gear... since it really does not have one, it has 1, OD,3, 4 (3rd and 4th being the intermediate band) and then 5th(OD) again. The OD servo bore is used for both 2nd and 5th. If you are getting shudder or stumble or DELAYED SHIFT POINT on shifting between 1&2 or 4th and 5th, it is the tranny with a worn servo bore (PLEASE READ AS: TRANSMISSION IS TRASHED BEYOND REPAIR AND MUST BE RE&RE AND PROFESSIONALLY REBUILT WITH A SERVOBORE KIT INSTALLED SEE WWW.SERVOBORE.COM) If you have this shudder or falter between 3rd and 4th, or all gears, then the transgo shift kit will fix you right up. The transgo shift kit can be installed from under the truck but does require you to remove the valve body from the transmission. I FOUND THIS A GOOD FUN CHALLENGE BUT IT IS NOT FOR THE MECHANICALLY DECLINED AND DEFINITELY NOT FOR THE BEGINNER.

I have felt as you and have replaced idler pully, tensioner, fuel pump, plugs, wires, ignition coil, etc. I rebuilt my tranny's valve body with a transgo shift kit which dramtically fixed the weak lock up (which I think is the problem you have) and I also replaced the tranny solenoid pack just to try and fix my OD.
Tranny shifts good and strong into 1st, 2nd, 3rd, and 4th better than it ever has as a result of the shift kit. OD is still not functional as my OD servo bore is worn. I have also tightened the OD band 1 turn in which reduced my 2nd gear defective shift point from 4500rpm to 3000rpm so at least the truck is driveable with no OD for now.

KEY POINT - **Engine and Transmission are integrated through electronics. If one is bad, the other also falters and/or trips codes.***

FYI - mine is an 03 XLT Explorer with 100,000 miles on it...aka... POS. I have no OD, OD light is flashing and Check Engine light is on. ATM Codes are P0732 and P0735.

I am now on my way outside in 40 degree weather to replace the UPPER INTAKE MANIFOLD gaskets which tend to leak and also result in rough idle.,, Bad running and bad shifting... the position I am in right now makes me upset especially since I crashed my Porsche this morning and now have to rely on this unreliable POS to get me around for a while.

My recommendation to you other than to sell the truck and beat yourself for buying a ford is to have a transgo shift kit installed into your transmisison which should eliminate your stumble in between shifts and to have the upper intake manifold gaskets changed (there was a recall on this). I do not work for transgo nor am I a mechanic, I'm a do-it-yourselfer so please consider the source of this information. I am simply documenting my findings, efforts and results.... more to come......

I have the exact same vehicle and similar problem - I too would like to say thanks in advance, and any help would be appreciated. We had been to Ford 3 times. They installed platnium plugs, wires, air filter, new timing chain guides (per a recall), fule filter, and did a genreal check. They said the idle was normal and never noticed anything unusual. We have over 800.00 in repairs so far and still have the probelm. Anyone got the answer?

DCN

 

[billsyzfr-1]

So I can purchase this, and install in my driveway? I'm a decent Meachanic, but all in all I just want to unload this vehicle.

 

[Richie_007_1968]

Ok, an update. Last Friday night I cleaned the IAC valce which dramatically improved my rough idle. Please note that I have 101k miles on this 03 Explorer. I did not change the upper intake gaskets yet but this is on my list as there is a recall on these. I purchased them and noticed that they are a rather soft rubber compound very similar to the gasket for the IAC valve. I'm thinking that a new IAC valve might eliminate my rough idle all together. Regardless, it is now running with an acceptable mild roughness. Good enough to drive or sell.

On Saturday I purchased a transmission and transfercase from an autowrecker for $1000 with 27k miles on it and had a local shop install it for $600. This investment has eliminated my start off vibrations, my lack of OD and makes the truck feel new again. I am confused as to really what to think of Ford as afterall, the truck at 100,000 miles is the same as what? 160,000Km's? In Canada it is not unheard of to put new drive gear in a 4X4 at 160,000Km's.

Now to answer your specific question. I would start with the $26.00 shift kit off eBay and install it yourself. Be aware that this is not a beginner's chore. The lock-up valve is very tedious so make sure you have ample small surface area tools and TONS of patience as you will need it. (I used a rough touch with the vicegrips and a delicate and controlled touch with a dremel tool) If this does not eliminate your trouble, replace the transfercase as this was the cause of my vibrations. I also noticed some seepage from the rear seal area of the transfercase when mine came out of the truck. Look for seepage on the rear seal of yours and if present, then you may need to replace/fix it as internal wear causes the output shaft to flex which is most likely the cause of your vibration. The flexing of the shaft degrades the seal which you can see so if you have one (seepage) , you likely have the other.

I have found that direct replacements from a wrecker was cheaper and FAR less painful that dealing with Ford. I could replace my tranny and xfercase TWICE for what Ford wanted to do the job once! There are enough wrecks out there now and some autowreckers may even provide installation services.

Good luck my friend, let us know how you make out.

PS - If it was a used truck when you bought it and it shifts hard, someone may have already installed the shift kit and unloaded it onto you. I did notice a very firm lock up after I installed the shift kit which from time to time would cause a bounce (single vibration)at shift from 3rd to 4th. The replacement tranny I installed shifts so smooth through all the gears it is like a new truck. I have never felt a tranny shift so smoothly, EVER and I have owned over 30 vehicles in my life so far. Also, as an FYI, I have been told that 5R55S and 5R55W are interchangeable, 5R55E is NOT. You would need to verify this if you swap out your tranny.

So I can purchase this, and install in my driveway? I'm a decent Meachanic, but all in all I just want to unload this vehicle.