Humming Sound From Corolla 2001 1.6Vvti

[Deggs]

My Corolla 1.6 vvti 2001 model 71000 on clock purchased 3 weeks ago, not sure if the noise was already there but I have what sounds like a small (hoover) sound coming from my engine bay when the engine is running, it does not change speed or pitch when running or changing gears, is this normal for this car.

Deggs