Idleing noise

[struttgart]

Hi all,

My 98 windstar has been adling really rough for the last week when it is cold. If I put it in park the noise goes away. My van has stalled a couple of times while in drive. What could it be?

Ciao,
Cory

[DRW1000]

Is your CEL on? If so what codes are you getting?

[wiswind]

Noise.....can be from the exhaust system....in particular shields on the catalytic converters being loose. When the car is in gear....there is a different stress....that can make more or less noise.
Rough idle could be from a variety of issues....
1. You could disconnect the vacuum line that goes to the EGR valve.....at idle, there should be no.....or VERY little vacuum to the EGR valve.
If there is much vacuum....spray a bit of "SeaFoam" into the vacuum line.....this will clean and lubricate the EGR vacuum control modulator....which is located on the back of the upper intake manifold.

Is less likely....but listed as a possible cause....sticking EGR valve. But as I said .....less likely.
Both of these SHOULD light the CEL (Check Engine Light).....but may be slight enough to not do that.

2. Clean the MAF (Mass AirFlow sensor)
Use a NON-residue electronic cleaner.

3. Look for a vacuum leak....a common issue on most cars nowadays.

4. Run some fuel injector cleaner through.....I recommend Redline Fuel System Cleaner....you can get it at Advance Auto now. Put the whole bottle in to treat a full tank of gasoline. If you have not done this before.....or for a while....you may need to do this twice.

5. The IAC (Idle Air Control) is a known failure item.
THis would cause an idle speed problem....your idle speed....when WARM should be around 500 rpm......
If it drops lower than this.....and then....sometimes stalls.....and/or sometimes comes back up (after making you think it is gonna stall)....then you want to suspect this item.
Can also stick at various idle speeds.
The IAC is on TOP of the upper intake manifold....next to the throttle body....It has a small cylinder on it....with an electrical connector.
This is what the computer controls.....to control the idle when your foot is off the accelerator......I.E at idle. The air bypasses the throttle body butterfly.
Anyhow....FORD says not to clean it.....but many have cleaned it successfully.