Ok. Ive been getting this loud sound coming from my engine compartment. I have trouble describing it but it sounds like a Loud Howling or a moaning sound. It is so loud that you cant even talk inside the truck. The sound only happens when the truck is idling or is coasting....pretty much when my foot is off of the throttle. The sound goes away the second i put my foot on the throttle. This kind of makes me think that it has something to do with the air intake. I have an Air Force One intake kit. I have a problem trying to locate exactly where the sound is coming from because if i open the hood it comes from everywhere. I have had a few people listen to it and they have no idea what it could be. The sound is very random. The only thing i can tell you is that it only happens when my foot is off the throttle and goes away the second i crack the throttle. Any input would be greatly appreciated.

 

It is coming from the idle air control valve. You must have deleted the small black box muffler when you added your intake. The muffler has to be in the hose to between the new intake and the iac like the original set up.

Do a search of fog horn and moosing for more info.

 

ONELOWF nailed her , or, nailed it. ? That doesn't even sound right now...? Well, he's right! There,that works.

Yea, they can do that when you remove the muffler(IAC).

 

I believe I still have the muffler box that goes into the IAC
Do these need replacing or maybe the IAC valve needs replacing?

 

Have you looked to see if a cat is hiding under the hood? Sorry, just had to!

 

You just need to put it back in the hose.