2003 windstar runs rough when cold

My wife has a 2003 windstar (3.8l v6).It idles ok when started, but when driven while cold it runs very rough.It smoothes right out and runs fine as soon as it starts warming up. We took it to the dealership to have it diagnosed.The mechanic said the intake gaskets were leaking. I had all the intake and plenum gaskets replaced at another garage. It didnt stop the problem, made no difference whatsoever. I dont have a code reader,and the mechanic who did the work said he wasnt getting any trouble codes. Any input or ideas would really be appreciated.

Probably the IAC. Check here for instructions how to remove and clean the IAC (thanks Wiswind) :

//leckemby.net/windstar/windstar02.html

(http://leckemby.net/windstar/windstar01.html)

It seems you mistyped the link, not a big deal, but when you click on it it will redirect you to the intake gaskets tutorial instead of the IAC cleaning. The right link can be seen by copying and pasting the web address or by clicking here (http://leckemby.net/windstar/windstar02.html)

By the way Welcome to the forum maliboo2001!

Best regards,

Oscar.

I checked the IAC as suggested, and it was relatively clean. It had a little soot but no build up, and the shaft seemed to open and close ok (wasnt all the way open, but wasnt closed either). I took it for a spin, and it still doiong the same thing. Something I think i neglected to mention before. When the engine is cold, if I rev it up and let off the throttle I can hear a rattle/vibration. It doesnt sound like valve or lifter chatter.Kinda sounds like a heat shield on a muffler rattling, but again it only does this when cold. I cant believe how good it runs when warm, when it runs so bad cold.
Thanks for the suggestion, it was definately worth a shot.
Thanks for the Welcome as well.

Is it a metallic rattling or more like a diesel engine?

If it's like diesel the problem might be the upper cover of the plastic intake, the baffle inside breaks and sits lose inside, it is a common problem. Try pushing down on the plastic cover to see if the noise will shut off.

If your problem is the other, try and trace were the noise comes from, if it's from below the van maybe the heat shield came loose and it's on the exhaust pipe, I've read that from other members in the forum. Also it might be an HO2 sensor, one came loose in my van and it had a metallic rattling sound mostly when idling and depending on which sensor came loose the PCM might not be properly adjusting the air/fuel ratio.

Best regards,

Oscar.

Have you checked for any vacuum leaks?

Ill check it out again sunday, maybe i can find where the noise is coming from. I did check all the vacuum hoses and connections i could, and didnt find anything obvious (no cracked hoses or anything unplugged).Someone at work suggested spraying starting fluid around different things to check for vacuum leaks, but I havent done it.
Thanks for the suggestions

Ill check it out again sunday, maybe i can find where the noise is coming from. I did check all the vacuum hoses and connections i could, and didnt find anything obvious (no cracked hoses or anything unplugged).Someone at work suggested spraying starting fluid around different things to check for vacuum leaks, but I havent done it.
Thanks for the suggestions

Spraying starting fluid is a good thing, just be careful and have an extinguisher at hand. Pay special attention to the hoses on the back of the manifold, I think there are 3 or 4 (one red, one green and one black, maybe two).

How long since the gaskets were replaced, maybe the van hasn't been driven enough for the PCM to trigger any DTC's?.

Another thing to do is to take the serpentine belt off and start the engine for NO MORE THAN A FEW SECONDS to make sure the rattling sound is/is not coming from any of the pulleys.

Best regards,

Oscar.

What I have read about, instead of starting fluid, is propane.
You take a propane torch.....DO NOT LIGHT IT....open it and direct the flow of raw propane in the direction of various places that you think the vaccum leak could be......like around the back side of the upper intake manifold, where there are a number of vaccum line connections.
Do not direct it near the air intake on the driver's side inner fender area.

The advantage of the propane torch is that it is a gas.....that will disperse quickly.
The starting fluid may leave a wet, flamable, area wherever you spray it.....which IS dangerous.

I have a picture posted someplace in my windstar pictures that shows the solution for a loose heat shield on a catalytic converter.
I bought the super big....oversized, hose clamps in the plumbing department of my local big box home center.
For my '96, the FORD TSB for the same problem showed just this solution.
Cheap and easy to fix.

Newer windstars, 1999 and newer, seem to have a number of posts about the coil pack failing.
This is also a possiblility, although I would expect a Check Engine Light (CEL) for that.
The epoxy body of the coil pack develops a crack, and the high voltage arcs through there.
The coil pack on the windstar contains 3 coils, each coil fires 2 spark plugs.
Along the same lines, spark plug wires.
One test that you might try.....when the motor is cold......and it is DARK outside.
Raise the hood, start the motor.....and while the motor idles, get out (gear select in PARK and parking brake set) and look around in the engine compartment....around the spark plug wires and see if you see any sparkles.
I have a friend who put an expensive set of Taylor high performance spark plug wires on his old Cavalier.
We were talking back and forth for something like 6 months about his rough running issue.
Finally, I told him to try the dark test.....and he told me that it looked like a city under his hood, his expensive spark plug wires were arcing all over the place.
Cold....moisture.....then when warm, the moisture is gone.....less arcing.

On my '96, I had issues with a slight miss.....that would get worse over time.
The only solution that I found for it was to run a Can or two of Berryman's B-12 Chemtool in a tank of gasoline about 3 times a year.
I have a picture posted in my windstar pictures that shows the buildup that seemed to keep developing on the spray end of the fuel injectors.
It does not seem to be a issue with newer windstars, but it is a cheap and easy preventative maintenance item.

The Fuel filter is another easy to forget maintenance item.
It is located under the vehicle.....just ahead of the rear tire on the driver's side.
A restricted fuel filter increases the workload on the fuel pump......and that is expensive as it is located inside the fuel tank....and the fuel tank must be dropped to get at it.