I just got a used 2002 Acura 1.7EL. with 103k km mileage.
Thing is when I go over 50km/h it starts making a humming/whistling/pitchy noise coming from the back that increases with speed.
Is it possible it's the brakes/discs which are kinda rusty? (see pics)
If not, what else could it be?
By the way...I do have to replace the brakes and discs...right?

 

wheel bearing

 

should i change all 4 of them or just the rear ones?
also..how do the brakes look?

 

VROOOM! HUMMMMMM VROOM! lol its not the back in the front. lol them intakes, i tell ya lol. kidding. dont listen to me.

 

i'm not saying it is the wheel bearing for sure, it just really sounds like a bad wheel bearing. generally, you replace only the bad one.
there are tests to determine if it is in fact the wheel bearing, but i'm not sure what those tests are.

 

Jack up the wheel and spin it by hand. If it is quiet, go to the other wheels.

If you hear noise, take the wheel off and take the brake caliper off to rule out anything related to the brakes. Spin the rotor by hand. If you hear any noise it almost has to be the wheel bearing. Any noise at all from the bearing means it fails this test. The noise from a bad bearing will get a lot louder at speed and with the weight of the car on it.

As far as your pictures go, the second picture is about the limit for grooves in the rotor but doesn't demand immediate replacement. The others look good. I couldn't see the pads. Of course you also need to inspect the insides of the rotors.

 

i did the wheel bearing "test"..drove at same speed at which noise occurs and weaved the car left and right to see if the noise accentuates and it didnt...so I'm guessing it's something else...any guesses?

 

Might be normal. I hear a whining noise from my tires when driving on grooved road surfaces.

 

well yeah, that is normal. but I'm talking on normal surfaces.

 

Directional tires that are put on the wrong way will be loud too. Look for an arrow on the side of your tires and if there is one, make sure it points the way that the tire turns when the car is moving forward.

But do the test where you just spin the wheel without the tire touching the ground also. Clearly that rules out any possibility it is the tire or the road.