Hum at 30+mph speeds, goes away when banking right?

[jenkins71]

Hello,

My 1988 325i 4 door sedan with auto trans has been having a weird hum or buzz when since I bought it.

The noise sounds similar to a tire rubbing on the body, though no tires are rubbing.

The noise varies with road speed, not engine rpm. It starts at around 30mph and gets louder the faster you go.

Today I went for a drive on the highway and noticed that when i swerved to the left to change lanes, the noise got louder. When I reached a highway junction, and the road had a long right turn to loop over to the other highway, the noise basically went away. Then when I was going straight, the noise came back. When I got off at my exit, the offramp was a long left turn, and the noise got much louder.

So on right turns, the weight shifts to the left and noise goes away. On left turns, the weight shifts to the right and the noise gets louder.

I'm thinking a bad bearing? Or could it be an axle? Anyone have any idea on how I could further diagnose this? Thanks!

[323i E30]

I’d also think wheel bearings with these symptoms.
Jack the car up, and spin your wheels by hand. See which one has play, or doesn’t turn as easily as the rest, or simply makes noise.
I’d assume the bad one is on the right side of your car, as the noise gets louder with added pressure there.

[82eye]

second a wheel bearing

[mbonder]

Wheel Bearing in the front.

[Fixedwheelnut]

Sounds like either front right or rear right bearing, when you turn left the weight shifts to load the right hand bearings, so if they get louder then they are on the way out, turning right the weight shifts left unloading the bearings on the right hence they get quieter.
Just need to determine if it is front or rear

[mbonder]

Usually the front will be much more sensitive to turning the steering wheel. If it's a rear bearing it will typically just change the pitch of the whine as your speed changes, if its in front you can get the whine to "turn" on and off as you turn the wheel.

[jenkins71]

Well, finally took the time to jack up the front end. It is definitely the passenger side front wheel bearing. Got a new one sitting on the shelf waiting for me to put it in. Thanks, guys.

[richardodn]

It's best practice to replace them in pairs, but it's not absolutely necessary to.