slyjackson

My explorer makes a loud humming noise that somewhat sounds like a "radiator cap " pressure escaping. It's not a hiss put a hum or roar. It is not metalic. It seems to happen every once in a while or when I am at idle for a while with the A/C running. I have checked all over the engine when this noise is present and can't seem to pin point the location of the noise.

Yesterday while I was walking in a store parking lot, another 1999 or 2000 explorer drove by and was making the same sound. I ask the guy did he have any idea what was making the sound. He had no clue either. He also has had his explorer in the Ford dealer to find the problem. No success with that either. It was driving him nuts too.

Does anyone know where this sound could be coming from and the cause? one more thing. After my explorer sits for 10 min or I drive it on the interstate for about 10-15 min. the sound stops. I know it is heat related but in what ?
Any help would be appreciated.

S. Jackson

slyjackson

I have found my problem (IAC valve) and I decided to post my findings and forward the info I got:

The sound is called "Moosing" which is caused by the IAC valve. It will resonate throughout the throttlebody/intake making it sound like it is coming from the MAF or airbox or everywhere.

You may need to clean or even replaced the valve.One quick way to find out is to pop off the small black cap on the IAC, all that is, is a small air filter, if that is clogged, it will produce the moosing sound I was hearing.

I have heard brand new IAC's do this from sitting on a shelf and collecting dust and also by making my new one do the same thing by taking off the "cap" and putting my finger over the hole ( was for demonstration purposes for a friend with a ford, he didn't believe me when I told him it could sound like a dying goose! )