The grinding noise when a car is in full left lock is usually caused by the tire rubbing against the wheel well liner or a suspension component. This can happen when the steering wheel is turned too far in one direction, causing the tire to make contact with something it shouldn't. It can also be caused by a loose or damaged wheel well liner, which can allow the tire to rub against it when the steering wheel is turned.
If you hear a grinding noise when turning the steering wheel, it's important to have it checked out by a mechanic as soon as possible. This could be a sign of a more serious problem, such as a damaged steering rack or a loose wheel bearing.
