OK this has been a issue since I bought the truck and it's only getting worse. Whenever the truck gets up to operating temperature the engine makes this loud humming like noise. Well today the noise drove me up a wall so I was determined to find it which I did. It's coming from the intake tube that goes from the air box to the intake. When the lid on the box is closed the humming is loud but somewhat quiet. But the second I opened the air box the noise got like 10x louder. I need to know how to fix this as I put 100 miles on my truck a day and I can no longer drown out the noise it makes.


Here's a poor sound clip taking from my phone, the sound isn't exact as my phone sucks. But you get the point it's loud.

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IAC is the common problem that causes this! Happened on my truck

 

Does it need to be replaced or can it be cleaned?

 

Try cleaning it. I replaced mine but just because i had a spare!

 

yep. iac. it's located on the intake near the throttle body. it sounds like it's coming from the filter area cause the sound travels down the intake tube.

 

iac.. get some sensor safe cleaner and spray it in and make sure you let it dry b4 reinstalling. should be 2 bolts,a plug and a gasket on it

 

Yep IAC once again. I had that problem. Just get a new one there not that expensive and they make the engine look cleaner.

 

ford redesigned it and has an extra spring in there to stop the humming.

 

will MAF cleaner work?

 

i dont think that is going to help, but maf cleanner should work.

 

i was told today to use carb. cleaner on the IAC. whats better?

 

actually if you can get ahold of GM top engine cleaner would be the best. but seafoam or carb cleaner will work also, carb cleaner will prob be alittle better than mass air flow cleaner.

 

i might need to clean this thing. I drove home from work today (about 20 minutes) and it idled crazy high THE WHOLE TIME. ive already cleaned the maf.

 

I called the dealer and the IAC was $145. The Auto Zone across the street from my work has one for $43.25. Is it a bad idea to get the Auto Zone one? I have the humming sound if i idle for a while, especially on warmer days. Embarrassing going through drive troughs... :)

 

same problem here as well. try cleaning it first but it didn't work for me....i had to buy a new one..............................

 

Here's an article concerning the IAC valve. I too am having problems with my IAC valve causing a humming noise in the air intake. I cleaned it with carburetor cleaner and set to let dry. It actually made it worse for me. The humming stopped, but the truck stopped idling high enough to prevent stalling.

This article is from Ford and you can take their word for it, to just buy a new IAC, but they only see it as a short lived solution.

Note: This is for a Crown Vitoria, but the application is the same. Here's the link to the article.

http://p71interceptor.com/repairs/iac/