Metal rubbing noise from left front wheel well.

It is possible that the broken tab is your problem because the tabs keep the hardware from moving, especially when you apply the brakes. To determine if this is the case, remove the tire,brake caliper, brake pads, and hardware. Put one of the lug nuts(or two if needed) back on to hold the rotor in place. Spin the rotor by hand and listen for that chirping sound. If you don't hear it, the hardware is the problem. If you can still hear it, check that metal plate that protects the back side of the rotor to make sure its not bent and rubbing against rotor. Also check that nothing is rubbing on the trans-axle(if its front-wheel drive). If all is well in these two places, the only thing left that spins in that area is the wheel bearing. They usually make more of a grinding or roaring sound but sounds can be tricky.. I am a mechanic for a car rental company and often have to diagnose problems by the sound they make. I hope this info is helpful.

Grinding is a sign on brakes in need of replacement. Your pads are worn through and now the metal backing plate of the pad is grinding up against the rotor. Replace the pads and rotors asap to prevent further damage.

Have the front wheel bearings checked they are a sealed unit that has to be pressed in or assembly removed and replaced. Or your brakes are dragging and rubbing against the rotor it could be the caliper is sticking or the rotor doesn't have enough wave, warp cut in it to push the pads back enough. Most people think a rotor is cut perfectly flat if this was true the pads would rub against the rotor all the time. The car could be jacked up and on stands and have someone listen for the noise right next to the wheel while you speed up the wheels and slow down with the brakes and don't try for 100mph you could hurt the tires

perhaps a stone has lodged in the brake caliper, or the bolts holding the caliper are loose, also check wheel bearing, and wheel lugs, either way it shouldnt make that noise and will need someone to look at it, it should be easy to see what is scraping

the noise is probably the ware sensors on the brake pads making noise the noise lets you know that the brakes are getting thin are are ready to be replaced.if you let this go to long you can damage the brake rotors, make sure you check to make sure the caliper is not sticking on the left side being this side is making more noise ,a stuck caliper can cause premature brake pads ware .

PATH: Brakes > Front Disc Brakes > Brake Disc (Rotor) > Removal & Installation Removal & Installation

1. Raise and support the front of the vehicle on jackstands. Remove the front wheels.
   
2. Remove the caliper assembly; do not let the caliper assembly hang by the brake hose, instead support it with a piece of wire looped around the front spring or control arm.
   
3. Remove the retaining screw from the brake rotor and remove the rotor from the hub.
   

An impact driver, No. 3 phillips screwdriver bit, and a hammer may be needed to remove the retaining screw. It is fairly easy to destroy the screw slots using an ordinary phillips screwdriver to remove the tightly driven screw (see photo).

1. To install the disc, replace the disc on the hub, screw in the retaining screw and replace the caliper assembly.
   

PATH: Brakes > Rear Disc Brakes > Brake Disc (Rotor) > Removal & Installation Removal & Installation

1. Raise and safely support the vehicle.
   
2. Remove the wheel and tire assembly.
   
3. Disconnect the caliper from the caliper bracket. Support the caliper out of the way with a length of wire. Do not allow the caliper to hang from the brake hose.
   
4. Remove the caliper bracket.
   
5. Remove the two 6mm screws and the brake disc. If the brake disc is difficult to remove, install two 8mm bolts into the threaded holes and tighten them evenly to prevent cocking the rotor.
   
6. Install the rotor in position. Install the two 6mm retaining screws.
   
7. Install the brake caliper. Install the tire and wheel assembly.
   

PATH: Brakes > Rear Disc Brakes > Brake Disc (Rotor) > Removal & Installation Removal & Installation

1. Raise and safely support the vehicle.
   
2. Remove the wheel and tire assembly.
   
3. Disconnect the caliper from the caliper bracket. Support the caliper out of the way with a length of wire. Do not allow the caliper to hang from the brake hose.
   
4. Remove the caliper bracket.
   
5. Remove the two 6mm screws and the brake disc. If the brake disc is difficult to remove, install two 8mm bolts into the threaded holes and tighten them evenly to prevent cocking the rotor.
   
6. Install the rotor in position. Install the two 6mm retaining screws.
   
7. Install the brake caliper. Install the tire and wheel assembly.
   
8. 
   

make sure brake hose not twisted. also possible shield from behind rotor rubbing its bolted behind hub & knuckle also check & make sure the metal shim for brake lining ears is not rubbing on rotor on the center edge. also sometime s there is a difference on inboard & outboard pads there is a dimple you may have switched. also with the wheel off & caliper mounted to knuckle you should be able to move in & out by hand if pins are good.

Is your ABS light on? If so, you have a bad wheel speed sensor at the LF wheel. Or, you may have rust buildup on the teeth that the speed sensor measures. Pull off the axle, and check the toothed gear that resided in the spindle.

If not, you may havea sticking caliper piston, or inadequate lubrication on the caliper slides.

You need to have your brake pads replaced. They make that sound when they get worn down so you know to change them. There is a little piece of metal that rubs on the brake rotor to tell you this. Hope this helps

either you have a caliper that has locked up and worn brakes down or it is just the metal that is in your pads making that noise. does it pull to either side when driving?