Humming noise with foot off accelerator over 80kmph

[Mustard]

I have noticed a low humming noise when I take my foot off the accelerator going at speed, usually above 80kmph. It is louder when taking my foot off at a higher speed. As soon as I put my foot on the accelerator pedal it stops, take my foot off it hums and will disappear when dropping below 80kmph.

I know the car is full of leaks, would that be a source? It is hard to pick where the sound is coming from but at a guess somewhere in the engine bay area. The sounds is also strange, a bit like a soft high pitch humming.

Any other ideas?

Cheers!

 

[Mustard]

Can hear from 32-37 seconds and then again from 48 seconds

 

[Aussie Trev]

Could be alternator on the way out.

 

[Mustard]

Thanks Trev, that could be it, I have noticed the lights are a little dim when I drive at night.