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

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: Check engine light and fuel cap stay on.

Hi there: In most newer trucks, like your 2014 Ram, if an error light is triggered and the repairs are made, you'll have to clear those stored error codes in the ECU with a digital scanner or they will stay...

Q: Creaking noise upon releasing the clutch

Hello. This is usually caused by either a worn out engine or transmission mount or an issue with a worn out suspension bushing. Either one will allow parts to move when they should be stationary and will cause this noise...

Q: My car stopped working while driving and fluid went everywhere

This is an indication that you have a major water leak or potentially a blown head gasket which is signified by the smoke and sluggish acceleration. This can happen when the car overheats and the cylinder head gasket is compromised....

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...
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...
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.