On my 2002 C240 40K miles when car is cold, only when I have the gas pedal depressed I hear a noise that sounds like a window motor running, I believe the noise is coming from the dash area near the glove-box or the transmission tunnel.

If I let the car cost at speed with no application of the gas pedal no noise.
The noise is low enough so that full throttle acceleration or even low-mid volume radio would mask the noise.

If car in park or neutral and stationary and I rev the gas no noise, and if car is moving and I slip it into neutral and give gas I hear no noise.

Any ideas.