Most of you have suggested that the following is an IAC valve problem:

- '98 Explorer in cold weather only (never in spring or summer)
- within 5-10 minutes of cold start there is a moaning/howling noise in/around the air filter housing
- most noticed when idling at stop
- will disappear if I give it gas but there is always a shudder like loss of fuel
- will do this only once or twice until engine is warm

Before I replace the IAC does anyone have any suggestions that it might be something else?

 

there are threads here on how to check the IAC and clean it i believe there both in the helpfull links but it does sounds like the IAC is the problem my 2000 did the same thing changed the IAC fixed the problem got at auto zone for like 32 bucks you might be able to get it at rockauto.com cheap aswell

 

Sounds like the IAC. Try cleaning it before replacing it.

 

It is the IAC. Sounds like a loud clothes dryer. Try to clean it first. If that doesn't work, replace.

 

To replace the IAC takes about 5 minutes. I bought a spare from a U-Pull yard for $5.00. I clean and swap them every fall. When I do the swap I clean the one I just removed and put it aside as back-up (or until the winter approaches).

The sad thing is that I have about 20 such "just in case" parts on my bench!!

I love my FORD!!

 

to test the IAC tap it with a small hammer ,it works everytime on my f-150 ,doesn't fix the problem just lets you knowif it is acting up

 

The 97/98 sohc v6 has an iac with a diaphragm, that is why it has a filter/vent on the side. If the diaphragm leaks it makes noise from sucking air through the vent/filter. This iac is about $100.00 at autozone, the iac for the 2000 is $39.00. Carparts.com has a borg-warner for $81.00 and I hear that rockauto.com is even cheaper. I just replaced mine with the borg-warner and it runs fine. I have heard that some people just remove the vent/filter but then you have an uncontrolled vacuum leak and suck in unfiltered air. 1 teaspoon of dirt causes about 50,000 miles of wear.

Hope this helps
Roy