1999 contour, hummm noise

I have a 1999 Contour SE Sport, 2.5 L V6.

I am getting a humming noise out of the Air cleaner box. It goes away when you push the accelerator but comes right back. This happens in park when we start the car, when I pull it into gear, and when driving and I let off the gas it does it for a couple of seconds. When it is in park and the humming is going on it flucuates the RPM's of the engine between 1200 to 800. It also seems to take some of the performance out of the engine when this noise is going during driving as if it is getting too much air.

I have changed the MAF, O2 sensors, PFE sensor. The mechanics told me they don't know what is wrong but it is not the fuel pump. They have cleaned the throttle plates and it seems to fix it for a day or so. It also pulls oil through the air cleaner box through the crankcase vent tubes.

Any ideas?

Clean the Idle Air Control located on the rear of the upper intake manifold. Its a common problem on V6 tours. It gets dirty and sticks, causing the car to idle roughly. I'm guessing the humming you're hearing is "the moose". Theres a how-to for the fix on contour.org's main page.

What is the "Moose".

What is the "Moose".

Thanks, Had no idea it had this kind of persistant problem with all of them. I took some time and researched the problem and this sounds like it is exactly my problem.

Thanks again,

James

Changed the IAC and everything is fine for now. Thanks again.