Bearing noise getting louder?

[pfhat]

So for the last month I've become gradually aware of an odd noise/vibration while driving at higher speeds and coming back to idle (i.e. leaving a highway).

It turns out the noise is there at normal speeds it's just harder to hear. It sounds vaguely like increased friction in a bearing or belt-based accessory. Slight mechanical noise, and some metal-on-metal buzzing throughout the car. It's real quiet but if you're paying attention you can tell.

I don't believe it's motor based as I can go into neutral at high speeds and the tone/feel of the noise does not change as the RPMs approach idle. The noise is directly proportional to speed of the wheels.

Any thoughts where to look? It's awfully tough to stethoscope while driving. I'm leaning towards wheel bearings, but there's no bumping or anything in the ride.

 

[JayRolla]

Sounds like wheel bearings, cv's or drive shaft.

Lift vehicle at all 4's. Rotate each tire and see if they have any play. Bad wheel bearings will cause tire to be lose almost like lose lug nuts.

You can also turn car on and put in drive, let another person run the rpms up as you listen and look for the issue. Just remember SAFETY first when doing something like that. Good luck.

 

[Buckaroo]

Good starting point to figure out it has to do with wheel speed. Some thoughts -
1. Tire noise will change when you change road surfaces (i.e. asphalt to concrete).
2. Wheel bearing noise is generally a low rumble which may change when you drive in an "S" pattern at medium speed with the bad bearing on the loaded side (outside) making the noise. You wouldn't typically notice any change in ride.
3. Differential noise is more of a whine which may change when you accelerate versus letting off the throttle and coasting.
4. The outside CV's may click when making a sharp turn at low speed.

Good Luck,
Buckaroo

 

[wc11]

Had my right rear done last April and this is what it sounded like.
https://www.youtube.com/watch?v=Qc3tnFbCK48