Wierd sound coming from the engine...

[shadowless127]

Lately i've been getting this wierd sound periodically from the engine, sounds kinda like "wooooooo" very low tone, almost grumbly. I can't seem to locate the source because everytime i pop the hood to try and pinpoint the sound, it doesn't make it .

Any ideas?

 

[uptownrockstar]

just to start things up.

do you think it could be the front wheels and not the engine at all.
do you think it could be the throttle position sensor. opening the throtte

just starting things up.

 

[Verno]

Sounds like the whistle of a bad IAC. Search for IAC threads here.

 

[daan-o]

Take the little black cap off (circle one) then it will come apart into 2 pieces, there will be a small black circle filter in there its probably filled with dirt and dust. Just rinse it out in the sink and rub it some, let it dry put it all back together. Some people say leave it off and you wont ever have the problem again, but i would recommend putting it back on because you will just ruin the valve faster. If that doesn't fix it you need to pull it off and clean it out with electrical cleaner here is a write up.
http://www.explorerforum.com/forums/showthread.php?t=84220

 

[shadowless127]

just to start things up.

do you think it could be the front wheels and not the engine at all.
do you think it could be the throttle position sensor. opening the throtte

just starting things up.

1) it's not the front wheels because it happens at idle as well as while in motion
2) If the throttle was openning i'd see it in the tach.

Sounds like the whistle of a bad IAC. Search for IAC threads here.

I didn't realize the IAC was an issue while in motion and on the throttle.

 

[black91EB]

I had a similar sound from my truck, turned out to be the alternator bearings. Pull the belt off and spin the alternator by hand, preferably with a mechanics stethoscope on it, and see if you can feel or hear any grinding or roughness.

 

[shadowless127]

After taking some time and listening to the truck at idle today, I deff think it's a dirty IAC. Will try and clean it this weekend.