Whining..... aghrrr

Ever since summer last year when the alternator decided to conk out there has been a slight whistle noise coming from the front at idle.
Today the car went in for a quick service, so I asked Mrmechanic to have a quick look.
It seems to be an air leak coming form the ISCV (Idle speed control valve).
Not long ago I had noticed the pipe coming from the ISCV to the crank case was looking shoddy and was very soft. I'm assuming this has failed and is letting air in causing the noise.
I'll swap the pipe with some new and see if it solves it.

Has anyone else come across this with their M52 E36?