Q: AC knocking when it is turned on

asked by on

I think there is either a problem with the blower or fan belt. When the air conditioner is turned on, it starts making a catching/knocking sound. As soon as it is turned off, it stops.

Hi there. It sounds to me as if your AC’s fan is interfering with something in the track of its spinning. Also your issue can point to your AC compressor clutch not gripping the pulley correctly. I’d suggest having a certified mechanic sent by YourMechanic come to your residence and correctly diagnose the air conditioner’s symptoms that your vehicle is experiencing.

Was this answer helpful?
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. AC knocking when it is turned on

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: Car overheats when I turn air conditioner on

The cooling system has two fans on most cars and one works to keep the engine cool with the A/C off and the other comes on when the A/C is on. The leaking fluid may be coolant from the radiator....

Q: When i try to put my vehicle into gear the shifter moves freely and will not go into any gear is a 2003 Cavalier what could that b

If you are unable to actually change gears, the possibility of damage to the linkage between the shift lever and the gearbox has to be ruled out first. The linkage might appear to move but it might not be moving...

Q: No heat-

If the heater hoses both are hot shows good flow through the heater core. The temperature control actuator is behind the glove box. You should operate the temperature control and see if the actuator is moving the blend door? If...

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...
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...
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.