Skip the auto shop - Our mechanics make house calls

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.

A: Hi there. It sounds to me as if your AC&#39...

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?

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: My a/c intermittently blows warm and cold air.

It is possible that your blend door actuator could be failing and going back to the default position. Many vehicles will default the blend door to heat mode. When the blend door actuator fails, it will automatically revert the door...

Q: Window broken

If the window will not operate at all, then it is almost always the window motor on this vehicle. This is a common failure. I would remove the door panel and see if there is voltage going to the window...

Q: Power lock relay not working?

Hello. Lock system issues are common with your 2003 Dodge Ram. When parts start to fail, it is usually intermittent and can be hard to find at times. The most common causes of failure are the lock switch, lock actuator,...

Related articles

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 P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...