Skip the auto shop - Our mechanics make house calls

Q: Knocking noise

asked by on

What can cause a knocking noise and when you put the a/c on it goes away

My car has 128000 miles.
My car has an automatic transmission.

A: The most common cause for a noise to go awa...

The most common cause for a noise to go away when the air conditioner is turned on is a faulty compressor clutch. There could also be a problem with a belt tensioner, or one of the other belt driven components. It would be advised to have it checked out by a certified mechanic, like the ones available from YourMechanic, to diagnose the noise firsthand for an accurate repair.

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

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: Oil leak

The most common leak on your particular car is the valve cover gasket. The gasket deteriorates over time and leaks oil over the entire engine. Before replacing the valve cover gasket, I recommend having a qualified technician thoroughly diagnose the leak...

Q: AC blows hot in the front, cold in the rear

Hello. It sounds like the blend door actuator is failing. This door is responsible for blocking off air flow to the heater core when the air conditioning is on. I would recommend having the blend door actuator tested using the...

Q: Getting error code P0128

This code is a sign that the engine did not get to operating temperature in a specified amount of time and the computer turns on the Check Engine Light. The most common problem is that the engine thermostat is partly...

Related articles

What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
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.