Peculiar Humming Noise...

[Gold98]

Hello all...I have a '98 XLT, and it is now making an odd humming noise. It happens at about 1/4 throttle when doing 25-30 mph. If it starts humming, and I give it more gas, it will stop. It sounds like its coming from the front passenger's corner...any ideas???

Thanks,
Gold98

 

[bigA]

Check your IAC valve. Mine made the exact same noise but only at idle. Replaced the valve, and good as new.