A week ago I cleaned my MAF, Throttle body itself (wasn't brave enough to disconnect all the hoses from the elbow to intake), and recharged the K&N. Now for the last three days I have noticed a slight howling noise. I checked under the hood this morning and the noise only makes its appearance when the engine is slightly revved up and when I take off slowly from stop sign or red light. I reproduced the sound under the hood and it seems to be coming from the air filter area. I did my search on the forum but couldn't find anything.

 

It is the sound of air getting pulled in. If you put the stock intake on you can still hear it but it is much much quieter.

 

No that sound is quite distinctive, its like a howling noise but only does it when revved a little.

 

I would just check it again to see if everything is hooked up solid.

 

Ok this afternoon had sometime to locate the noise and I took a video of what I think it is. I removed the IAC and cleaned it thoroughly but still makes the noise. When I remove the hose from the intake tube to the IAC it's louder and when I partially cover the end of the hose with my finger it doesn't make the noise. Do I need a new IAC?

Here is the video
http://www.youtube.com/watch?v=0PHeYH26Cd8

 

You know what motor you have in there? Reason I ask is because both V8's have different IAC locations as well as IAC horns. The Horn is up front on the 4six and in back on the 5four. I'm guessing it's a 4six without a horn.

EDIT! I didn't see your last post,hang on.

 

Yea, you need to put the horn back on lol.

 

That's a 4six BTW.

 

jbrew, is that the horn on the right side of the throttle body? Reason I ask is that the K&N was on the truck when I bought it and I haven't removed anything. Yes it is a 4.6, in the video to the right of the TB? Also it only recently started making this noise, I have put almost 100,000 miles on this truck without this noise. (03 131,000 mi.)

 

About the IAC , -did you work the mechanical inside, like the plunger while cleaning. The plunger usually ends up with hard carbon deposits on the shaft.

But if it's idling and running fine, the IAC is working as it should. The noise will come and go. Check your connections, like the other guys mentioned in this thread and keep in mind that anything you work on that has to do with air metering, you need to reset the KAM (disconnect the battery for about 15.)

Should toss that K&N and get a good filter for that truck. - Just a thought.

 

Jbrew, it idles fine the only issue is the noise and it stumbles when I get on the throttle not WOT but moderate acceleration.

 

What cleaner did u use to clean the MAF with?

 

Can't remember the brand but it was specific for the MAF.

 

Good. Some clean but leave a residue so I thought the hiccup could have been that.

 

x2