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.

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
  1. Home
  2. Questions
  3. Humming noise

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: Grinding noise shifting in reverse and clutch goes to floor

Hi there, thanks for writing in about your 1988 Pontiac Fiero. It sounds like the clutch is dragging and not releasing properly. The problem could be with the clutch itself (warped disc or pressure plate), or a problem in the...

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: Clutch or air conditioning work.

Hello. It is rare that a clutch is ever replaced on today's vehicles. On your Honda, the clutch it not a replaceable part. You should always replace the compressor as a unit to prevent further issues. Keep in mins that...

Related articles

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...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
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.