Strange behavior at idle

I have a '99 Rodeo, 3.2 V6, auto. Just today I noticed that at idle, or any time I am not pressing the gas pedal, even when I am moving, I hear a continuous squealing noise that sounds electrical in origin. At first i thought I might be picking up electrical noise that was being played through my speakers but when I popped the hood the sound is distinctively coming from inside the engine compartment, but it is so loud i can't tell exactly where it's coming from. if I manually adjust the throttle, the noise stops. The noise does not sound like a belt or pulley. My fluid levels are good. The noise is not there when I first start the engine, but it starts to happen once the engeine has warmed up. Driveability is not affected, but I can't help but think that something is not quite right. I installed foglights last weekend, but disconnecting them/pulling the foglight relay does not make a difference.

Any thoughts?

This sounds like a bad intake manifold gasket. The vacuum leak caused by a split IMG will cause idle quality issues and can sqeal loudly from the area they are split. Air rushing past the split causes the plastic gasket to vibrate like a reed and make noise. Try a search for "IMG" or "intake manifold gasket" and you will find tons of stuff.

G/luck
Joel

Hey there:

What I do because of loss of hearing in one ear. I'll take a heavy piece of paper roll it up into a cone and point the small end to the engine. It helps me to locate wierd noises in my car. Once your over the stupid look of it, it helps me just fine.

2Cents
paul

Ok, now the sound seems to have gone away but now the ABS light has come on. Any chance these are related?

I had a ABS light come on in my 92 3.1 v6, it was a bad sensor.

I did have an erratic idle once, it turned out to be a vacuum leak by the throttle body. I don't think you have a throttle body, but take a look at the routing of your vacuum lines, the map is up under the hood and feel every line for leaks!