Front end grinding noises while the car is in motion are a symptom of a mechanical malfunction or failure that demands inspection. Diagnosing the problem is a matter of inspecting certain parts of the car that are the common cause of front end grinding noises. Most causes of front end grinding need to be addressed and repaired by a professional auto mechanic.
If the grinding noise occurs when you apply the brake, then the brake pads may be worn out and no longer make smooth contact against the brake rotor. Check the brake pads for composite material between the brake rotor and the backing plate of the brake pad. If the brake pads are worn out, they should be replaced.
Check the engine mount and transmission mounts to see whether they have separated and allowed the engine or transmission to settle onto the frame of the car. If this has occurred, the engine mount or transmission mount should be replaced.
Check the axle bearing for failure. The axle bearing is made of high grade steel and functions to support the vehicle's weight so the wheels rotate. When it fails, metal contacts metal while the car is in motion. If this is the case, the axle bearing should be replaced.
In a vehicle that utilizes a standard transmission, you may hear a grinding noise when changing gears. This indicates a failure of the clutch assembly that prevents the engine from disengaging from the transmission when the car comes to a stop. In this event, the clutch assembly should be replaced.
If the grinding noise occurs when you turn the steering wheel, then the power steering system may be low on fluid. Steering the car in this condition may be difficult since the power steering system is unable to transfer the necessary force from the engine to steer the vehicle. Check the fluid level of the power steering system and add as much as needed. If the problem continues, then there may be a leak somewhere in the power steering system. Take the car to an auto shop to inspect and repair the power steering system.
If the grinding noise occurs when the engine starts, then the flywheel may be damaged. This means that the teeth of the flywheel are worn out and are unable to mesh with the start drive gear. The flywheel should then be replaced.
If the grinding noise occurs under normal operation while the car moves at speeds of at least 45 miles per hour, then check the tread pattern on the front tires for scalping or other wear. Check the suspension to see whether one or more tires are unbalanced. An unbalanced tire does not make consistent contact with the road and results in uneven wearing of the tire treads. This produces a grinding sound when the wheels move at higher speeds. The suspension needs realignment, and the damaged tires should be replaced.
