my vw polo has a grinding noise only when it is raining when the weather

[Joe]

Where is the noise coming from
Front
Back

is it a constant noise
does it get louder or change pitch with speed
does it only happen when turning or going over bumps?

Wheel bearing or CV joint or even slipping belt?
really need lots more specific information

 

[Lawrence]

is dry you dont hear it .? the garage can't find anything wrong with it .it does sound like a rusty spring to me .any suggestions
hi it sounds like it is coming from the back it is heard mainly when going over bumps or an uneven road but wheni it is dry no sound at all. i have had it checked for the bushes in the wheels but they are ok