There is a loud sound coming from my wheel which sounds like metal scratching metal as it rotates around a wheel. It happen on a very warm day, could it be that brake rotator expand due to warm day and cause it to touch the brake pad? This is on a 2007 S40, so I know Volvo had a few defective parts.

 

Sounds like the rotor. The pads and rotor expand on a warm day.

 

After looking for any piece of metal that could got stuck in the wheels which I found none. Yeah I think your right the rotors and pad expanded but I havent had that problem lately and couple days it got warm.