I have a 2001 Expedition with 42,000 miles that I bought new. Other than a new battery, a set of tires, and changing the oil & filter every 2500 miles -- it has never had anything done to it. It has never been back to the dealer since day one.

I ordered the car with all the heavy duty stuff and trailer towing package, and it has never been used to tow -- so it's had a pretty easy life; and always run cool.

Normally my wife drives the car, and she reported to me that it was "jerky" going up hills. My first instinct was that it was due for a fuel filter.

I took it for a drive and found that long full throttle acceleration was smooth; easy driving was smooth; but slight acceleration up a hill produced the jerky affect. It felt like it could be an engine misfire, or a transmission glitch -- maybe hunting between 4th and 3rd gear; or, possibly the torque converter not staying locked.

If I lock out the overdrive, the problem seems to disappear.

1) The transmission fluid is full, cherry red, and there is no burned odor.
2) The overdrive light is not flashing.
3) There are no codes.

Sorry this is so long, but thought I'd check and see if anyone has any ideas, before I make a date with Ford.

Thanks

 

My first thought would be that you have a COP going out.

 

Wouldn't that throw some kind of code?

 

COP's don't throw a code until they completely crap out. Neither do injectors. I'd check both of them.

But, it sounds (unfortunately) that it is the torque converter. Have you had the tranny flushed yet? Might be time!

 

It needs one of two things. A new set of spark plugs and find the misfiring COP to replace it,or a trans fluid change. I'm much more suspicious of the COP and need for a set of plugs.
JL

 

It sounds more like a tranny issue to me as well. At 42K miles, you're overdue for a tranny fluid/filter change if one has not yet been done.

 

^ x2 - Have it flushed & see if it clears up the problem since it is close to needing it anyway. If it's still there, start hunting down the bad COP's. I doubt it needs plugs, but if you are in there it might be worth changing them anyway.

 

Because you indicate that long full throttle acceleration is smooth, it does NOT sound like you have a COP going bad. A bad COP usually gets worse as you place it under a load(hard acceleration).

Sounds like it's in your transmission.

http://www.performancedistributors.com/soscoils.htm

 

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Yeah -- I'm thinking it's probably the trans. I have a couple of long hills by my house, where I was able to keep the throttle wide open for a long time -- fastest that car has been in a long time. It was very smooth and seemed to pull better than my 2008 F150.

It seems like the fuel filter, coils, plugs, injectors, etc -- would break down under the heavier load, if they were bad.

And, the fact that the problem goes away when I turn off the overdrive, also leads me in that direction (transmission problem).

I wonder if changing the fluid (which seems fine and has never been overheated) would do any good -- or if that'd just be a waste of time and bucks.

Probably need to get it over to Ford -- I've got a pretty good dealer that always seems to treat me right. Wonder if they'll fix mine or put in a rebuilt? Thanks.

 

Ahh but injectors seem to show their problems at partial throttle positions.

 

Well, on that theory, it would be easy enough to run a couple cans of injector cleaner through it -- and see what happens.

Any particular brand better than another?

 

seafoam - just put a can of it in about 1/2 tank of gas.

But, if you've got a cracked injector, this won't help much.

It's quick to check the injectors. You only need a 7mm socket and some lightweight motor oil.

Pull the 7mm bolts from the fuel rail, pull it straight up, and inspect each injector for cracks or busted tips. Lube the o-rings back up and reinsert them. Trust me - you DO NOT want to skip the lube part - it will tear the o-rings and you'll have to do the job again with replacement rings.

Start to finish, figure an hour total.

 

Just an update -- I dumped a can of Chevron Techron (AutoZone didn't have Seafoam) in the gas tank (1/4 full) and ran it down to almost empty -- and much to my amazement, it seems to have fixed the problem. Thought I'd be replacing the trans.

As I mentioned before, it's never been touched since new (now @ 42,000 miles); and I typically buy the cheapest gas I can find -- so I guess the injectors were just fouled.

Perfectly smooth now. Thanks Bnovak.

 

Good to hear it's running smooth again.

 

My 2003 does this sometimes.Are cop's expensive?