Q: My car AC make noise when on but quiet when off. I just replaced the entire system less than 2 years ago?
There is a rattling noise, but AC does still blow cold. From time to time it makes a loud humming noise. It is a Hyundai Sonata 2004, 4 door car.
Recommended Services
| AC Compressor Replacement | $715.49 - $3134.49 | Get a Quote |
| Car is making a noise Inspection | $94.99 - $114.99 | Get a Quote |
It sounds like you may have an internal component of the AC compressor failing. It is possible to be a bearing or another non serviceable item. I suggest having a certified technician, like one from YourMechanic, diagnose the noise firsthand to determine the exact cause of your concern.
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
What others are asking
How do you start the engine with the smart key system?
If your car is equipped with the smart key system, it means that you don’t have to use a key to crank the car. You have a start/stop switch. Using it for the first few times can be a little...
Car making noise like something is loose.
I would have a technician inspect the car for the noise (https://www.yourmechanic.com/services/car-is-making-a-noise-inspection). If something is loose it could be dangerous to drive.
What is the recommended tire inflation pressure?
It is very important to always have your tires properly inflated. The proper tire inflation pressure is located on the Safety Compliance Certification Label or the Tire label, which are on the B-Pillar, near the door latch, or on the...
Headlights not turning on
The headlights on these vehicles are controlled by the lighting control module on the left side of the dash. This module is controlled by the light switch which tells it to turn on or off. The control switch will need...
Service Airbag light goes on and off
This vehicle has many technical bulletins that pertains to wiring issues with pins and connectors to various modules and control units in the vehicle. This issue is one that is hard to track down since it is an intermittent connection...
My car is making a squealing sound when it cranks and when I turn on the A/C
Hi, thanks for writing in. What you're describing sounds a lot like an AC belt (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-ac-belt) that is loose or the serpentine belt on your alternator loose (or a combination of both). A common mistake that some mechanics make is...
Do I have a problem with the electrical system?
Hi, thanks for writing in. The charging system is not very complicated. If the alternator and the battery are absolutely 100% good, no doubts about it, then the issue is likely a bad ground. Both the battery and the alternator...
Dealer where I purchased the vehicle stated my rotors were "all rotted" at my last service. Quote - $375.00 per axle? High?
Hello. 'Rotted' is an unusual term for brake rotor problems, but here we are. With your mileage, especially if you have lots of stop-and-go driving, brake service may be required. Dealers have a fairly high cost structure (building, test equipment,...
2004 lincoln ls waht makes the rear end sway
It sounds like you may have a broken or damaged sway bar or stabilizer bar. A sway bar or stabilizer bar is a steel bar that connects suspension components on opposite wheels. Its purpose is to combat body roll when...
Related articles
A Buyer’s Guide to the 2012 Hyundai Accent
Hyundai Hyundai has become a force to be reckoned with in the automobile industry, as they have been improving many different elements of their vehicles – under the hood and with the exterior styling. The 2012 Hyundai Accent is proof...
How to Buy a Good Quality Heater Blower Motor Resistor
Vehicles Vehicles that are equipped with a manual HVAC, or climate control, system utilize a blower motor resistor to control the speed of the heater blower. If you are driving a minivan or an SUV with a separate rear passenger...
Symptoms of a Bad or Failing AC Pressure Switch
If the AC is cutting on and off rapidly, unable to cool the cabin, or failing to turn on the compressor, you should replace your AC pressure switch.
Browse other content
Cities
Maintenance