I just recently replaced all my pads and rotors. Just afew days ago I started to notice that there is a loud pulsating vibrating sound coming from one of the rear tires. It usually starts off some what quiet and it progressively gets louder as I go faster. 70-80 on the highway. I think it's coming from the rear right tire but I am not certain. I kind of think that it might be the rotor rubbing against the pads but the weird thing is that after about 10-15 minutes of driving at highway speeds the pulsating vibrating noise slowly goes away. I installed the slotted stoptech rotors if that helps. They look really nice and stop well. Anyways... It's getting very annoying and I'm at a lose as to what could be wrong. I really need help! Any suggestions?

 

Could be a rotor that's out of round. Check your tire pressure too. Sometimes overly inflated tires will do this. Could also be flat spots in the tires from sitting overnight that eventually goes away as the tires warm up and the rubber becomes more malleable.

My crappy Falken FK452's do that a ton but my Nitto Motivo's do not.

You could have also knocked a wheel weight off in the process of working on the tires but I would think it would continue to do this all the time if that was the case rather than go away after a while.

 

Ball bearing

 

I'll check the tire pressure today and see. If the rotor is out of round then what does that mean? I have to order a whole new rotor? And tires wise, I don't have anything special. I think they are the RSA eagles if I remember right. I like them. I've used them ever since I got the car and they are pretty cheap. Haven't caused any problems yet. I just don't know why it would be making this noise now. Also, the first time I noticed the noise was also right before I replaced my rotors and pads. I left for about a month and a half and I didn't drive it and when I came back and drove it the first time, it made the same noise. My rotors and pads were really bad, I honestly should've changed them sooner. I just had alot of other stuff on my mind. Once I changed them though the noise went away. But now it's back again. It seems like it could possibly be a bearing because I don't know what else it would be at this point. I've heard those are a pretty expensive fix though. Freakin cars.

 

You think it's a bearing even if the noise goes away after 10 minutes or so? I would seem to think that it would stay and not fade away if it was a bearing. I could be wrong though. I've never driven a car with a bad bearing.

 

I did not even see the "goes away" part. Bearing noise will not go away unless changed out. I take my answer back.

 

Is it a scrape? A metallic sound? Rubbing sound?

Could be:

Dust shield rubbing on rotor
Slotted rotors do sometimes make a "wiping" noise as the pads pass over the slots
Tire issue (can you temp rotate the tire to other side to confirm noise stays)
Bad bearing (usually doesn't go away, but I've had bearings louder on rainy days, than sunny days)
Gerbil in wheel

 

I'll have to check to see if the dust shield is rubbing. It's like a pulsing sound. Rubbing like for sure but not metallic. Weird thing is, I went out to drive today, and the sound was almost completely gone. Whenever it does come up though, it rubs and vibrates so much that my rear view mirror vibrates as well. Since its a pulsating, rubbing, vibrating sound, it makes me think that something is not aligned correctly. I just don't know what because its acting so weird. Needless to say, the whooping sound/vibrations still go away after only like 10-12 miles of highway driving. I'm at a loss.

 

Can you distinctly identify which side it is?

Swap your rear tires temporarily on a dry day. Go for a ride and see if the noise changes sides. If it doesn't then the tires aren't rhe cause

 

I went ahead and took the tire off and the whole caliper assembly off and put it back together. I don't think it's a wheel bearing problem. I think my rotor is just warped somehow. Although now that I put everything back together the pulsating sound is gone and now there is a scraping metallic sound but only when I break hard. Something that also makes me think it's the rotor being warped is that there is an INTENSE amount of heat coming off just that rotor. All the others are alot cooler. Also I'm pretty sure it's the rear left, not the right. So I'm not sure what to do at this point.

 

Seized rear caliper? Were the slide pins freely moving? Was the piston tough to push in?

 

I figured it out and it was very dumb. The whole problem was that when I last took my tires off to replace everything, after driving 200 miles or so the lug nuts must have become unevenly loosened. That cause more pressure to be put on one side of the rotor making it tilt. That then cause one part of the rotor to rub against the pads making the pulsating sound I was hearing. This friction then caused brand new brake pads to be completely worn out in a matter of 50 miles or so. I guess the moral of the story is to always check your lug nuts. Also if it does matter, the longer slide pin with the bushing on it goes in the top, not the bottom. Don't mix them up. Now she drives like a champ again. Hope this helps anyone else who might encounter this problem!

 

Glad you got it figured out. Sometimes doing your own maintenance can bite you in the a$$ but at least you probably learned from it and will be aware of both things next time. Be careful torquing down those lug nuts too.. doing so with improper technique can lead to problems and damaged rotors and lugs.

 

Factory lugs and wheels?

If not, it could be an issue of the lugs not fitting the wheels properly which caused them to loosen up that way.

 

Where they torqued down properly? I.E. torque wrench