What is this noise please? Volvo C70
 

Dear All,
Just started getting this noise in my C70 Convertible, does anyone know what it could be and how to fix it please? This noise is when the engine is idle as well as when I am driving. It's a 2010 Volvo c70 convertible diesel 2.0 automatic.

Please note I thought the noise was coming from the climate control / air conditioning but it does not go away even after I switch off the AC / blower.

Many Thanks
Aman