Skip the auto shop - Our mechanics make house calls

Q: Low hovering/humming (not high pitched) sound driving over 35mph.

asked by on

Whether accelerating, coasting, or breaking, the sound persists. Just noticed within the past few days. From forums, wheel bearing seems to keep coming up, but they usually refer to a "helicopter" noise, which this is not. Mine is steady, not choppy, and no shaking of vehicle. Any thoughts? I just want to be semi-prepared for what it might be (or isn't) before taking to a mechanic.

My car has 84000 miles.
My car has an automatic transmission.

A: Hello there, thank you for asking about you...

Hello there, thank you for asking about your 2006 Chevrolet Malibu. Failed wheel bearings will not typically cause the vehicle to shake. They will instead make exactly the noise you are describing: humming. Although humming is typical, there are other sounds and frequencies that will occur depending on the failure mode. If the bearing race is really "destroyed" (pitted) for example, it’ll sound like you’re driving on a gravel road; the noise will be loud. Wheel bearing failures can mimic tire defects, including merely abnormal tread wear. YourMechanic staff will typically apply wireless chassis ears to the four wheel bearing positions. Using wireless pick-ups, a channel receiver set next to the driver will identify the wheel from which the noise is coming. You can ride along and see it for yourself. In some cases, though the bearing failure is so obvious that merely "loading and unloading" the vehicle suspension on a curve will identify the wheel position. Your bearings are bolted on assemblies so they are straightforward to replace; you need not worry. Also, for your application it must be determined whether the mounting bolts are re-usable. The FSM for many GM vehicles of your type states in huge print: DO NOT re-use the wheel bearing mounting bolts. That is because those bolts are typically tightened to 90 ft lbs., which is very tight, and when you start reusing a bolt already subjected to high stress, they tend to weaken and can fail in the field. At any rate, the first order of business is to rule out tire noise. Once that is done it is a simple matter to identify the wheel position. Also, if a front bearing has failed, you might consider replacing both sides as the other may not be far behind. Finally, buy the part from AC Delco. In other words, don’t get the cheapest one you can find, even if it says "guaranteed forever," which has no meaning insofar as the quality of the part. Another good vendor is SKF. If you would like help, a technician from YourMechanic can inspect the noise in your vehicle and make the necessary repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: I have a 2000 mecury mountaineer. When driving spots in gears between 30 an 40. There is no back fire just misses.

The transmission has an accumulator spring that may be broken or the shift valve in the control module may have a broken spring. If an accumulator spring or a shift valve spring breaks in a transmission, the shifting will be...

Q: My transmision won't go into reverse, or D, and it doesn´t have neutral.

Hello. From what you describe it would appear that your transmission may have a serious issue. There are shift solenoids and pressure switches that can cause issues with shifting, however the symptoms you describe, along with the brown fluid, may...

Q: Need to know minimum pad thickness on 2010 Malibu

Hi there. The GM certified service manual states to replace the brake pads when the friction material has come within .76mm of the mounting surface. The mounting surface is the metal part of the brake pad that the friction material...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.