Cold Start - Rough Idle

Fran D · 04-22-2008, 01:30 PM

I have an '01 Windstar with ~130K miles. Plugs, wires, coil pack, fuel filter all under two years old. Dealer had replaced intake isolator bolts when it was ~40K miles old.

This is a problem that has just emerged over the past several weeks. No changes or repairs had been made to the vehicle previously. On a cold start, and ONLY a cold start, it will turn right over and run...idle fairly well...then, when I put it in gear, it starts idling very roughly and will hesitate a little when trying to drive away (tranny fluid is full and was changed about two years ago). It is never to the point of shutting off, just a bit of a rough stumble. However, about two minutes, or so, into the run time, it starts idling as smooth as glass. There are no issues, at all, after that point. This happens, now, over and over on a cold start. If I start up while warm, there are zero issues. I've looked to see if some actuator is moving in that time frame, but I haven't been able to find anything with my scan tool.

I've searched this forum, but most results state, "check the tune," which means plugs, wires, etc., and I know they're OK. I'd appreciate some further insights/input to see if I can track this down.

phil-l · 04-22-2008, 04:48 PM

This sounds like a classic sticky Idle Air Control (IAC) valve to me. It's a common problem, and easy to deal with.

Everything you need to know is right here:

http://leckemby.net/windstar/windstar02.html

Many sources will claim the IAC should be replaced; I've always had great results just cleaning the valve.

Fran D · 04-23-2008, 01:28 PM

Well, that seems simple enough. I'll give that a shot and see what happens. If it doesn't work, I'll be back here whining.

phil-l · 04-23-2008, 02:40 PM

Let us know how it works for you!

northern piper · 04-23-2008, 02:58 PM

is cleaning the IAC with wd-40 still the best spray? I know there are a lot of different spray cleaners out there. I'm about to do mine and want to know if wd is the best.

Piper

phil-l · 04-23-2008, 04:26 PM

Personally, I like Berryman's B12 ChemTool cleaner.

That said, the IAC only tends to have intake-related goo on it (exhaust goo - like in an EGR - is far tougher to clean); most any cleaner or lubricant/solvent - including WD-40 - will do the trick.

Fran D · 05-04-2008, 03:30 PM

Well, I finally got around to cleaning the IAC (I had a water pump emergency with another car). It was pretty gunked up and I tried to clean it the best I could, but the plunger wouldn't move very freely. It probably requires a replacement.

What horrified me, though, was that when I took off the IAC and looked down into the one manifold port that's closer to the passenger side, there was a pool of oil sitting there!

It looks like the port that communicates with the PCV. The PCV didn't appear stuck, but it was very oily together with the hose end that connects with the intake manifold. I replaced the PCV to just see if that cleans it up. It may be that my rough idle wasn't due to the IAC, but just the first couple minutes of burning off the oil!

Ed_Strong · 05-04-2008, 11:27 PM

I would soak the plunger end of the IAC in WD-40 overnight and then work it loose and then give it a good flush with Carb Cleaner spray before buying a new one.

The oil pooling is not a PCV failure but a Ford design flaw on the Valve Cover that allows too much blow by to be drawn back into the intake manifold thru the PCV system which is the major cause for the Isolator Bolt problem aka. P0171 & P0174 trouble codes. The Valve Cover flaw was updated on later models by replacing the baffle inside the cover.
You can either buy a new updated Valve Cover or fix yours with intructions found in this forum (I tried seaching but it's not letting me at the moment... sorry)

Fran D · 05-05-2008, 12:28 PM

Quote:

Originally Posted by Ed_Strong

...You can either buy a new updated Valve Cover or fix yours with intructions found in this forum (I tried seaching but it's not letting me at the moment... sorry)

The only thing I could find that looked like a DIY fix, were a couple of posts on putting a filter in-line with the PCV hose. Is that what you're referring to?

Also, I thought that the valve cover issue was a 99-00 problem. That wasn't solved for '01?

Thanks for the help.

mundy5 · 05-05-2008, 01:57 PM

i've seen the posts Ed is talking about. It requires the screwing of some sheet metal on the inside of your valve cover. but you might be right. you could have the redesigned cover.

northern piper · 05-05-2008, 02:06 PM

you can easily check to see if you have the new cover. Just remove the pcv valve (with engine off) and look in at the 5 o'clock position. You'll likely need to shine a flash light in to see. I you see a 1/8" hole, you have an old design cover. If you don't see a hole, the cover is the new design. On my replacement cover (for a 2000) the space where the hole was actually had a little metal dimple, kind of like how an electrical box has knock outs that aren't knocked out until you remove them. This 1/8" hole is a contributor to the oil that you have accumulating in the pcv hose/intake/iac

piper

Fran D · 05-07-2008, 08:52 AM

Quote:

Originally Posted by northern piper

you can easily check to see if you have the new cover. Just remove the pcv valve (with engine off) and look in at the 5 o'clock position. You'll likely need to shine a flash light in to see. I you see a 1/8" hole, you have an old design cover. If you don't see a hole, the cover is the new design. On my replacement cover (for a 2000) the space where the hole was actually had a little metal dimple, kind of like how an electrical box has knock outs that aren't knocked out until you remove them. This 1/8" hole is a contributor to the oil that you have accumulating in the pcv hose/intake/iac

piper

Well, as it turns out I do have the new-style cover. I can see the knock-out dimple, just as you described, but it's more at 11 o'clock looking from the front of the car. Nevertheless, it had been sucking oil like nobody's business through the PCV. So, I know that the valve, itself, isn't suspected, but I'll have to wait and see whether the replacement cleans it up. Since I've repaired my daily driver, the van isn't driven as much, so it may take a few weeks to get any results.

northern piper · 05-07-2008, 10:16 AM

check out this thread for how I addressed the "oil suckage" problem.

http://www.automotiveforums.com/vbul...d.php?t=902544

mundy5 · 05-07-2008, 10:44 AM

thank you piper for your solution.

however, i wonder why it is even doing this in the first place. something is out of whack to make the motor oil go up the pcv line. i wonder if it did this from day one or if something can be done. as much as i like your solution piper, it still doesn't seem to solve the actual problem. you have effectively dealt with its most distressing symptom.

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