2004 Pontiac Aztek Brake rotors

Brakes problem
2004 Pontiac Aztek 6 cyl Front Wheel Drive Automatic

I need to replace the front brake pads, and need to know whether the factory rotors are thick enough to be turned or whether I need to replace them as well. The mileage is approx. 90,000 km, no hard driving, rotors don't appear to be warped, and only slightly grooved.