If the grinding noise only happens when applying the brakes, rust could have formed on the rotor surface due to the water. Run the car around and apply the brakes lightly intermittently and the noise should go away. Check the brake pads first, maybe they are about to wear out.
If the noise happens with the engine on without driving, one of the pulley bearings could be worn due to water getting to them.
If the noise only happens while driving, water might have got into the wheel bearings and damaging them.
Sorry I am unable to provide any costing.
Sunday, June 22nd, 2008 AT 2:33 AM