Help with F150 rough idle/hesitation/vibration

[Rowski]

Stephen

I haven't worked on a 2001 Ford truck yet. I have had a drivability problem on a 1999 that I wrestled with. I'm pretty sure you have a problem with the ignition system. I'm also pretty sure your truck has COP (coil on plug, it sits directly on the plug) ignition system, that means there is a coil for every cylinder. There are also no ignition wires per say, more a short spring with a boot to connect the coil to the plug. The plugs are not that easy to get to, not as hard as some and not as easy as some either. The sooting (called cloaking) is normal and does need to be cleaned at regular intervals. Fuel filter is good to change but probably not your problem. The "wells" that the spark plug sit in can sometimes get moisture in them, causing a miss or rough idle.

Is the check engine light on?

What engine size?

Have you driven through any water or very wet driving conditions?

I have the testing specs at work on my information system.

Make sure you get the OEM recommended spark plug. Its either single or double tipped platinum. Your parts store can let you know what is recomended, I know the Napa parts store can.

Just a note. If your deelaer did install a new idle air valve they should have cleaned the claoked throttle either as part of diagnosis or after the part got put in. Do your self a favor and don't let that tech work on it again. Also I would ask why they replaced the idle speed motor. What was the reason? One should not replace a part unless it tested bad, or directed to by a TSB (technical srevice bulletin). As you know, it was not a proper fix and as far as I'm concerned the idle speed motor has very little to do with your "rough idle & hesitates under light acceleration".

 

[hazmat]

Derek,

No check engine light

5.4L V8

Haven't driven thru water. Occasional rain storm, but the truck has been acting up since the winter. Doesn't seem related to weather.

The idle air control valve was replaced around march. The rough running is getting more regular thus my attempt to fix it. Ran fine on the way into work this morning. But too early to tell if cleaning the TB fixed it.

Should I put new plugs in? I've been searching around F150online.com. Seems that everything under the sun has caused the rough idle, dirty idle air control valve, 02 sensor, plugs, coils, camshaft sensor. The list goes on & on. /forums/images/graemlins/confused.gif

Thanks for the help.

 

[KENSFM]

Steve,
Have you had to replace any tail light bulbs lately? This is usually the first sign that you should have traded in the truck to avoid these type of problems. /forums/images/graemlins/grin.gif
Seriously, before this problem drives you crazy /forums/images/graemlins/crazy.gif (pun intended) I would take the truck to a GOOD local FORD dealer and let them take a look at it. Believe me it will be money well spent in my opinion.
Ken /forums/images/graemlins/smile.gif

 

[boustany]

Bird

I always warn people about Winstar, so here goes:

There is a known defect associated with the front coils on Winstars. The coils break, usually instantly shredding the tire. In my case, it also destroyed the front brake circuit and did all kinds of other damage.

This happened the day after mine was serviced at the dealer. /forums/images/graemlins/mad.gif

Apparently, for most models this is "fix on failure". For me, the good news is Ford paid for the repair.

The bad news is, it almost cost me my family.

/forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif

Fortunately, my wife had exited a highway when the destuction happened and was able to regain control of the vehicle.

Apparently, the same problem exists with other Fords, and they fit a sort of cage to protect the tire.

In any event, I have seen 3 other Winstars suffer this fate. No fatalities yet.

I owned the car for 5 days after the repairs were completed. Long enough to get a new Sienna. All of Toyota, over the history on file in Canada has had fewer recalls than my 1996 Winstar.

Go figure.

Please look into it. We need your posts on TBN

 

[JD4610]

Stephen,

I do driveability work at a large Ford dealership. As you found out, the symptoms you describe can be caused by literally hundreds of things. With a little more info I may be able to point you in the right direction.

You describe the problem as a rough idle and hesitation under light throttle. A hesitation, as it's name implies, is a delayed response to throttle application. You hit the throttle, and nothing happens for a split second or so then the engine takes off and runs like normal. Are you sure it isn't more of a miss, a loss of power on one or more cylinders that makes the engine vibrate and kind of chug along? I'm not trying to be picky, it's just that you'll need to look at more or less completely different things depending on which it is.

As you now know, the 5.4L engine uses a coil-on-plug ignition system, with individual coils for each cylinder. These coils have a reputation for failing, especially on cylinder number four, which is on the passenger side closest to the firewall. This would give you a miss symptom (vibration/chug-chug.) They aren't that hard to replace, but cost about $110 each for a newer updated design. You may be able to reproduce the symptom by gently brake torqueing the truck at about 1/4 to 1/2 throttle when warm. Don't do this for more than a half minute or so as it gets the trans fluid pretty hot.

I'll agree that what your dealership did was a poor diagnosis and repair. The air bypass valve (IAC) doesn't do much except control idle speed. However, contrary to what was mentioned earlier, they shouldn't have automatically cleaned the throttle body when they did the repair. As a matter of fact, this is expressly forbidden by Ford. The throttle body has a non-stick coating on the inside that can be damaged by some solvents. Removing this coating can lead to a binding throttle later on. Yes, many techs clean them anyways sometimes, myself included. But it shouldn't be expected as a matter of course.

Unfortunately, unless you find a way to get the truck to act up on demand or the computer sets a code, this won't be an easy problem to diagnose and would be best left to a dealership with the proper diagnostic equipment. My best advice would be to find a better dealership, or at least a better tech at the last one you went to. Don't be afraid to ask the shop manager to put someone good on it. He knows who the good techs are.

Good luck and let me know if I can help.

Jay

PS: You do pull your tractor with this truck, right? (Obligatory tractor content.) /forums/images/graemlins/grin.gif

 

[hazmat]

<font color="blue">You describe the problem as a rough idle and hesitation under light throttle. A hesitation, as it's name implies, is a delayed response to throttle application. You hit the throttle, and nothing happens for a split second or so then the engine takes off and runs like normal. Are you sure it isn't more of a miss, a loss of power on one or more cylinders that makes the engine vibrate and kind of chug along? I'm not trying to be picky, it's just that you'll need to look at more or less completely different things depending on which it is. </font>

Jay,

You are right - It is more a loss of power & chug. Sounds like the consensus here is that its a coil problem. Thanks for the help. It ran OK today.

Yes I do trailer the tractor with it see pic.

 

[bgott]

As bad as his problem sounds it ought to have popped a misfire code, don't you think? At least a pending code anyway.

 

[Bird]

</font><font color="blue" class="small">( defect associated with the front coils on Winstars )</font>

Are you talking about the coil springs? This is the first time I've heard of that happening. Our Windstar is a 2001 SE Sport so if they had such a problem with the '96, I would have expected it to have been corrected in 5 years (of course that doesn't mean they did /forums/images/graemlins/wink.gif).

 

[Rowski]

</font><font color="blue" class="small">( However, contrary to what was mentioned earlier, they shouldn't have automatically cleaned the throttle body when they did the repair. As a matter of fact, this is expressly forbidden by Ford. The throttle body has a non-stick coating on the inside that can be damaged by some solvents. Removing this coating can lead to a binding throttle later on. Yes, many techs clean them anyways sometimes, myself included. But it shouldn't be expected as a matter of course.
)</font>

This "special" coating that Ford uses doesn't apear to special at least not in my eye. Its main purpose is to keep the cloaking down to minimum. So if the throttle bore has cloaking the coating is not doing its job. There are cleaners out there that are gentle and don't harm the coating. Ford also says that replacment is needed if the throttle body cloaks.

Give me a New Generation Star Tester (ford OE scanner), my Snap-on Vantage (graphing multimeter), good 4 channel lab scope and Alldata one shold be able to fix it. A really good skilled diagnostician doe not need codes to fix a problem. But It sure does make life easier.

There are a few good techs that work at dealerships. They are hard to find as a customer because the dam service writter gets in the way. Another reason (my opinion) is that a lot of dealership techs become part changers. While this maybe an effective way of fixing problems it leads techs to become lazy and have poor diagnosic skills.

Jay, these coments are not directed to you personally. For you might be one of those few "good" techs. I myself think I'm one of those "good" techs, always learning more. Usually 2 or 3 times a year I'll get a car a dealership couldn't fix and I eventually fix. I wish I didn't like living in the counrty and working with my tractor so much because I've had some real nice job offers including Snap-on Tech saleman, Snap-on technical training instructor, Numerous dealership and larger indepent shops. I just like what I have now.

 

[Rowski]

A missfire code would turn on the engine light might even flash the engine light if the miss is bad enough. Pending codes would not turn on the engine light. But usually missfire codes don't need/use 2 trip logic (to set light) due to a miss being a major cause for emissions (Feds did this).


Stephen

Do you wash your engine compartment?