Skip the auto shop - Our mechanics make house calls

Q: it makes a loud humming noise when you run the ac

asked by on

when you turn the ac on it makes a loud humming noise

My car has 150000 miles.
My car has a manual transmission.

The noise is most likely coming from the A/C blower motor in the dashboard. The blower may have excessive build up of dust collecting on the fins or has sucked something into the blower causing an imbalance to it. I would remove and inspect the blower fins in the evaporator case, located behind the glove box.

If you’d like to get this fixed or simply want a second opinion on this, consider YourMechanic, as a certified technician can diagnose the issue with your A/C and help you fix it accordingly. Good luck.

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: Honda Element air conditioning is blowing warm air at lights last year we replaced the fan condenser (2) and it did it today again

You will need to have the computer for the powertrain scanned since it controls the a/c compressor and fans coming on. You could have a clutch cycling switch that is bad.

Q: Helicopter noise / vibration when driving.

Hi there. The noise is coming from the transmission. The noise could be a gear set inside the transmission with a broken tooth causing the vehicle to shake and sound like a helicopter. I recommend seeking out a professional, such...

Q: I have 2015 dodge dart and it's makes a high pitch screeching sound on idle not consistently is it normal? Dealership said it is.

Hello, thank you for writing in. The noise you are hearing is not normal for most properly functioning engines, and although the damage may not be obvious right this moment, the component at fault may be on it's way out....

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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.