loud whinning sound from air intake

[HAWK53]

when the temperture is above 70 degrees there is a loud whinning sound from the air intake. it is not caused by the air filter, its extremely annoying. it does not occur in the colder temps only on warm days. my mechanic heard it and couldn't find it's source without a more extensive search. It" a 99 explorer xlt 6 cly engine. it doesn't happen all the time, but often enough . mostly when idling or at low speeds

 

[dreamr]

It is likely the IAC (Idle Air Controller) that is howling. As it gets progressively worse it starts sounding like a foghorn

Do a search of the forum for details on the subject. Many say cleaning it will help, I say toss it and buy a new one After isolating it as your issue of course,....

PS welcome to the site

 

[DeathsArrow]

Better that it sounds like a fog horn than when you can't get it to idle anymore.

Try a cleaning first, if it goes away, plan to replace it anyway.

 

[HAWK53]

fog horn

tnx for the reply got any idea where the the idle controller is

 

[floydr007]

take off that plastic cover that says 4.0L SOHC. Its sitting right underneath it, and is attached to a wire and harness. Just unclip it and 2 bolts takes it off. Installing a new one takes all of 10 minutes.

 

[BrooklynBay]

It's right on top of the manifold in the area where the intake hose goes into. It is right near the "butterfly" that opens when you hit the accelerator pedal.

 

[dreamr]

Driver side of the engine, It looks like a little tomato paste can bolted to the intake. I'll see if I can dig up a picture for ya with the search function.

 

[dreamr]

This thread should show and tell all.....

http://www.explorerforum.com/forums/showthread.php?t=84220&highlight=IAC+Picture

 

[BrooklynBay]

That is an excellent link with a lot of detailed pictures. Here is one picture from that thread:

 

[HAWK53]

tnx ordered one today, took it off and it looks dirty inside. New one will be in monday and ill change it. I wont know if it works till the summer comes.

 

[spindlecone]

What aftermarket intake do you have?

 

[Raminator157]

Mine was howly really bad. I took it off and cleaned it out with a rag. I did not use any cleaning agents. The Hayes Manual said not too. It hasnt done it since and its been 5 months.

 

[HAWK53]

I Have No Idea What Intake I Have I Assume Its Stock, The Aic The Parts Store Gave Me First Was The Wrong One It Had Large Sort Of Rectangle Holes Instead Of The Smaller Round Holes So I Brought It Back And They Said There Was Another One But They Had To Order It

 

[mora0004]

I have a 99 xlt which had that same whining noise in warm temperature. The noise went away after I replaced the Head gasket which required me to replace the intake manifold gasket.
Extra air gets into the enging through the leaking gasket. This air is unmetered since it bypasses the Mass air flow sensor. This causes erratic ideling.
There are many threads concerning this intake gasket problem in this forum.

 

[HAWK53]

I Dont Have Any Idling Problems Only The Whinning Noise In The Summer. It Runs Fine In The Winter

 

[HAWK53]

Replaced It Today

I replaced the IAC today and the engine is idling nice and even where it went up and down before, wont know if the noise will go away until summer when it gets hot