Skip the auto shop - Our mechanics make house calls

Q: There is a rattling sound when you turn the A/C on and you put the car in gear. Does not usually rattle if car is not in gear.

asked by on

There is a rattling sound when you turn the A/C on and you put the car in gear. Does not usually rattle if car not in gear.

My car has 55580 miles.
My car has an automatic transmission.

A: If the rattling only occurs when the A/C is...

If the rattling only occurs when the A/C is on, you can conclude that the rattle is coming from the A/C system. If the rattle occurs without the A/C on, then you will need to dig deeper. You have clearly stated that the rattle occurs when the A/C is on, so I will address that as so.

When you put a car into gear, you add load to the motor that is felt from the accessory belts all the way to the wheels. Of course you feel this in the steering wheel and in your seat when you put it in gear. I suspect you have a serpentine (drive) belt tensioner problem. Tensioner’s manage all the load that occurs from the accessories mounted on the front of your motor. The A/C is unique among these accessories. A/C systems have other issues that can creates rattles, but they are much less common and difficult to explain in this forum.

In addition to the A/C system, you could have an exhaust shield that comes loose. The added load placed on the motor from the A/C system may be just enough to create such a rattle. There could be a loose pipe or hose that is made to rattle more with the added load of the A/C.

Your car is fairly new and I would not expect something like this from a newer Honda. I have to wonder if something such as an accident or off roading experience may have led up to this. If anything like that has occurred, I would suspect this is a result of it. One other possibility to note, there are reports of some CR-V’s having timing chain rattles. But they don’t seem to accompany the A/C being on. So hopefully this isn’t your issue, because it is a much bigger repair.

If you are still unable to figure this out, a certified technician from YourMechanic can come to your car’s location to inspect the noise and make proper repairs.

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: white smoke when cold

When the vehicle is first started your exhaust pipes are cold and if outside temperature is cold the exhaust pipes are even colder. Now you start the engine and the hot exhaust hits the cold pipes causing a large amount...

Q: Won't shift when warm

Hello there, many different faults may be causing your 1988 Chevrolet C2500 not to shift. The most common would be low transmission fluid, shift linkage, transmission range sensor, shift solenoid, or a mechanical transmission fault. Have a qualified technician, such...

Q: Not shifting and quit running - 2011 Honda CR-Z

With your description of the problems, it sounds like your vehicle is having problems with the clutch slipping on the engine flywheel. 60,000 seems pretty early for this type of problem, but depends on the way the vehicle is driven....

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...
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...
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.