Weird humming sound help!!

[lidomane]

I noticed it the other day and completely took me by surprised, I was driving late at night going about 30-40mph, nothing crazy. Im cruising along when I notice a deer on the side of the road so I just begin to slow down when it suddenly decides to run across the road, I just barely miss the thing but all of a sudden this weird humming sound starts, I first think that its my brakes, rotors, or calipers because I know for a fact that I HAVE to change them, they are long over do but i digress. I start to try to speed up and my car is feeling very sluggish and the humming sound is kinda loud, my passenger is also noticing it as i ask her just to make sure im not just hearing things, i thought the calipers and rotors maybe got stuck but im finally able to brake somewhat normally again but the humming sound wont go away, every time i speed it it gets louder and when i start to slow down it goes back to being some what loud, and i also can feel a vibration in my steering wheel that wasnt there before the sudden braking. I start to think its my motor or trans that is going but the gears are still changing nicely and normal (I have an automatic btw, 72K miles), i change my car into "manual" because my car has like the A and M buttons and I start to shift my car and its going fine and i decide to switch is back to automatic and the sound is still continuing even after being in both drives. I try to start driving like normal again and maybe about 5 minutes later the sound just stopped and didnt come back the whole night. Ever since then if i break a lil "too" hard, the sound will come again and my car will feel like shit and the vibration in the wheel will commence. I now changed the front brakes, rotors and calipers to new crisp ones, but i did not replace the rears as the brake pads still have alot of "meat" on them. After changing all of that, i drove the car and still after suddenly braking the sound starts again. I will mention though, if i turn off my car and let it sit for like an hour or two the sound will not appear again, only after I brake hard will the humming sound start. Sorry that this was very long and hopefully not confusing, but if anyone has any clues or ideas please let me know, and i will add that im by know means a mechanic or car guru, im just a guy that enjoys cars and TRIES to work on his car while learning a few things along the way.

[shogun]

Moved from Forum Software Questions & Suggestions to E36 forum

[importbanana]

Do your brakes get hot for no reason after you've driven normally? Maybe stuck calipers? When you brake hard they maybe don't back off from the rotor.

When replacing brakes, did you check or lube all the caliper parts that should move freely?

[spyderg0d]

Sounds like your abs unit is stuck on and pulsing or pulling the brakes on a front caliper. It can be many things.
The brake travel sensor
The abs speed sensor
The abs ring on the wheel bearing
The abs relay
The abs unit itself

Most are easily checked. The wheel speed sensor can be checked at the plug, if the sensor is good you can check the wheel speed ring WITH the installed good wheel speed sensor.
The abs relay is a simple replace.
The abs unit is more of a "diagnostic tool" thing as you have to control it with a tool and see how it reacts, unless you just swap it for a known good one. This is the most expensive thing, and a pita to bleed properly without mentioned abs scan tool/controller for bmw.

[lidomane]

I wouldnt say that they get hot, but at the same time when i was replacing my brakes i noticed that there was like nothing on them, it was down to the brake wear sensor it was essentially burning that aswell. And yes everything should be moving fine.

- - - Updated - - -

Sounds like your abs unit is stuck on and pulsing or pulling the brakes on a front caliper. It can be many things.
The brake travel sensor
The abs speed sensor
The abs ring on the wheel bearing
The abs relay
The abs unit itself

Most are easily checked. The wheel speed sensor can be checked at the plug, if the sensor is good you can check the wheel speed ring WITH the installed good wheel speed sensor.
The abs relay is a simple replace.
The abs unit is more of a "diagnostic tool" thing as you have to control it with a tool and see how it reacts, unless you just swap it for a known good one. This is the most expensive thing, and a pita to bleed properly without mentioned abs scan tool/controller for bmw.

Ill look into it, thank you! No ABS light is coming on on my dash, not sure if that would matter or not, but ill check out what u have told me and write back. Thanks Again!