Ford Windstar, Engine Revs

MORESNOWDAYS

MEMBER
2002 FORD WINDSTAR
6 CYL
FWD
AUTOMATIC
147,000 MILES

I brought my 02 Ford Windstar in for recall work, and got it back one week later. Now that I have it back I notice that when I hold at a steady speed, the engine will rev 100-200 rpms quick, and go back to normal. It happen every 15-20seconds. I've tried, and it happens, at different speeds with cruise control on and off.

I called the dealer asked them, they said that the part of the wire harness changed under recall was for the cruise control, and shouldn't affect anything else.

Not sure what it could be, it also seems to run slightly rougher, and downshift slightly harder than it did before the recall work. The recall work also consisted of the front and rear subframe reinforcements being installed.

5 Replies

JACOBANDNICKOLAS

MECHANIC
109,758 POSTS

I don't see where the work they did would cause the issue that you are having. Have the idle air control valve checked (IAC). If the check engine light is on, ask them to scan the computer to see if there are any related codes stored in the computer.

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Wednesday, April 27th, 2011 AT 2:05 PM

MORESNOWDAYS

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I pulled the IAC, cleaned it out with carb cleaner, and checked it the only way I could think of. Plugged it into harness, grounded it against the manifold, and had someone turn the key without starting the engine. Made slight noise, but no movement at all. It stays in a slightly opened position. I'm thinking this is a safe way to say it's bad, and ordered one from NAPA.

I don't have any lights (CEL or others) on, so I don't think I would get much back for codes.

Other than waiting for the IAC to show up tomorrow and swap it out, not sure what else to do. Any other thoughts?

Napa thought maybe the throttle position sensor, but the screws holding mine on are stuck real bad. I don't want to ruin them pulling it if it isn't necessary. I also don't know how to check this one.

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Wednesday, April 27th, 2011 AT 4:51 PM

JACOBANDNICKOLAS

MECHANIC
109,758 POSTS

The pintel on the end of the IAC should move. It is what determines the idle speed by allowing air to bypass the throttle plate. If it isn't moving at all, make sure there is power to it. If there is, I think you found the problem. I don't feel the TPS would cause the problem you described. Make sure you check for vacuum leaks too and if you haven't, try cleaning the MAF sensor. There is a special type of cleaner used. Most parts stores will have it.

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Wednesday, April 27th, 2011 AT 6:44 PM

MORESNOWDAYS

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I've figured out that what is actually happening is the transmission is momentarily dropping out of overdrive, which is why I see a momentary 200rpm spike on the tach.

After cleaning the IAC with carb cleaner, it ran good for a short while, but then started acting up again (especially when the A/C is on). So, I got a new IAC sensor from NAPA. They assured me it was the correct one. Looks the same and mounts the same. Only slightly different plunger to control air.

I installed it, and it runs worse than before. Started up the motor, and idled fine, but jumps up 700-800 rpm when the steering wheel is turned. Also is worse when the AC is running. Then it will jump in RPM when I turn the steering wheel (while at a stop), then stall.

I tried wiggling the connection to the IAC with the motor running and can hear it opening. It seemed like it would cut in and out if I wiggled it right. Also, seemed like it ran better with the IAC unplugged.

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Monday, May 2nd, 2011 AT 12:54 AM

MORESNOWDAYS

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4 POSTS

After cleaning the IAC with carb cleaner, it ran good for a short while, but then started acting up again (especially when the A/C is on). So, I got a new IAC sensor from NAPA. They assured me it was the correct one. Looks the same and mounts the same. Only slightly different plunger to control air.

I installed it, and it runs worse than before. Started up the motor, and idled fine, but jumps up 700-800 rpm when the steering wheel is turned. Also is worse when the AC is running. Then it will jump in RPM when I turn the steering wheel (while at a stop), then stall.

I tried wiggling the connection to the IAC with the motor running and can hear it opening. It seemed like it would cut in and out if I wiggled it right. Also, seemed like it ran better with the IAC unplugged.