Q: Loud grinding sound when turning both directions - 2006 Mazda 3

Depending on the location and the specific sound you are hearing, this could be either power steering or CV joints going bad. Generally, CV joints, when going bad, will make more of a popping or clicking sound and will cause a bit of vibration that will be felt when driving the vehicle. As you may know, the CV joint is the final connection between the transmission and the wheels, transferring power from the transmission to the wheels.

The power steering pump may be causing a slight grinding or whining sound when low on fluid or when it is failing. The power steering pump works in connection with the rack and pinion system as well, and when the rack is not functioning properly or allowing fluid to flow properly, this can cause the power steering pump to work harder than normal making this kind of sound. I would suggest having an expert mechanic, such as one from YourMechanic, come to your location to inspect your car to determine why there is a noise when turning.