So I upgraded the snout pulley and the coupler and supercharger oil was changed as far as I am aware. I dont believe the needle bearings to the rear of the supercharger were touched.

I did hear a noise very similar the other day to the noise I originally had but have not been able to hear it again and havent been able to visit the garage again since lockdown was imposed. I will try and capture the noise this weekend if I hear one and post it.

The easy test for noises is to take supercharger belt off (as suggested earlier) if you hear the unwanted sound and see if you can still hear the noise after. If the noise disappears you know at least it is the supercharger causing the noise. Range Rover Vogue SE 2007 L322 4.2 Supercharged 121k. Engine rebuilt @ 120666 Miles