Skip the auto shop - Our mechanics make house calls

Q: Humming noise

asked by on

No warning lights have come on and car runs fine. It recently started making a 'revving' or humming noise when I start the ignition. Noise goes away by 20-30 mph and is intermittent.

Today radio stopped working and car asked me to enter security code.

Not sure if these 2 problems are related and may indicate a more serious problem.

My car has 181000 miles.
My car has an automatic transmission.

A: It is possible that you could be having an ...

It is possible that you could be having an issue with your alternator bearing. The alternator is responsible for charging the battery and is ran by the serpentine belt.

The pulley that is connected to the alternator has a bearing that can dry out and make a humming sound. The best way to resolve this issue would be to replace the alternator.

I would recommend having a certified technician, like one from YourMechanic, diagnose the noise firsthand to determine if it is truly the cause of this issue. They'll be able to replace your alternator as necessary if it's proven to be faulty and address the issue with your radio as well.

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・Save up to 30%

Get a quote

What others are asking

Q: Error code P2442

Hi. The code P2422 is an "EVAP canister vent shut valve close malfunction" code and is a manufacturer code that needs a little diagnosing before it can be replaced. If you need further assistance, I recommend you have a mechanic,...

Q: Can you operate safely with the trunk lid open?

Having the trunk open while the engine is running is not a wise idea, although it may be necessary in some instances. Your car’s exhaust contains carbon monoxide, which is toxic and cannot be seen or smelled. If the trunk...

Q: Startup problems, no dashboard lights but the headlights and radio are on

A faulty ignition could cause an issue where some systems receive "key on" power and others do not. If the vehicle is not starting with all dash lights and systems operational it could be an issue with the immobilizer circuit....

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 Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...