Possible causes
Tyre condition and tread pattern
The sound can change after fitting seasonal tyres or on a different road surface. Uneven tread wear is also worth checking. The noise appearing after a tyre change does not prove the cause by itself.
Wheel bearing
A worn bearing can make noise as the wheel turns. How loud it is and where it seems to be from inside the car do not reliably identify the side that needs repair. SKF recommends confirming the source of the noise before replacing the assembly.
Other rotating parts
If the sound changes when you accelerate or lift off the throttle, tell the mechanic. A description like 'one wheel is humming' does not rule out a source elsewhere in the car. Checks and several clues together are needed.
What to tell the mechanic
- At what normal speed you first notice the noise and whether it builds gradually.
- Whether the sound changes on a different surface and whether it appeared after a tyre change or a hit to a wheel.
- Whether the hum comes with vibration, a metallic noise, pulling to one side or a warning light.
What you can do
If a loud metallic noise appears, the hum suddenly gets much louder or the car no longer responds normally to the steering, stop in a safe place and call for assistance. Do not test the bearing with sharp lane changes and do not accelerate on purpose to make the noise louder.
Where the check starts
The mechanic finds the exact cause during the inspection.
Frequently asked questions
If I hear it on the right, should the right bearing be replaced?
That is not enough to conclude. Noise can travel through the body and mislead. An inspection is needed both to find the cause and to choose the part.
What should I say when I call the workshop?
Say when the hum started, the car model and any recent work on the wheels. At Titan in Chișinău you can ask for a running gear and tyre check. Whether it can be repaired and the cost are confirmed once the cause is found.