The air conditioner in your vehicle Is meant to keep you comfortable whilst you’re driving in hot temperatures. If you’re driving on a hot summers day, it’s important that you’re able to get your car cool so that you don’t feel flustered or light headed when you’re driving – this can lead you to faint behind the wheel and this isn’t good.
If the temperature is too cool, it can cause your hands to become stiff – this can prevent you from holding your wheel properly or being able to change transmission. The ac system is meant to keep quiet and it should be able to do its job without causing any disruption to the driver. If you hear a rattling or clicking noise coming from the air conditioner, this can cause you to lose focus and this isn’t good for drivers. When sounds are coming from the air conditioner, there could be a few reasons why.
The AC system in your car is a separate system and it’s connected to the engine by the serpentine belt. The serpentine belt is a long snaking winding belt that’s meant to keep the alternator, power steering pump, air conditioner and sometimes the water pump running smoothly. The belt turns the pulley at the AC compressor and the compressor is engaged and disengaged by an electromagnetic clutch.
The Reason Why the AC is Making Noise
If you turn on the AC and you immediately start hearing noises, it could be one of a few reasons below.
Compressor – if the AC compressor is failing, it can cause the AC to make weird noises. It’s quite unusual for the compressor to fail because it has a life span of 10-15 years so if your car has been around for that long, chances are its broken. A faulty AC compressor could be caused by dirt building up in the condenser coils. This means that the AC can’t exhaust heat from the system and its force to run constantly. The increased pressure can cause the compressor to fail which can lead to the weird clicking and rattling noises.
Another reason for the compressor to fail is that the suction lines are blocked. When AC refrigerant lines become blocked, you’ll notice the cooling of your vehicle isn’t effective. If the problem isn’t fixed, then the compressor could fail.
If the refrigerant charge is low, it can cause the compressor to fail. The refrigerant lines can develop cracks, and this can cause refrigerant to leak. When the levels become too low, the compressor has to work hard to pump the low refrigerant through the system to get your car cool.
Another reason that the compressor could fail is that the refrigerant line is too large or small.
Pulley – if the pulley bearings fail, this can cause noises to come out of the AC. To tell If the problem is coming from the pulley, you can check to see if the pulley is visibly worn out. Overtime, the pulley spins against the belt and both components start to wear out. This can lead to scuffs and marks on the surface of the pulley – this can be noisy, and you’ll be able to hear it from the AC.
Belt – if the serpentine belt is worn out, it can slip and this can causes noises to come out the AC. Overtime, the serpentine belt can wear, fray, crack or become glazed and the rubber can start to peel off the belt. When the belt begins to slip, it can cause noises to come out of the AC.
The serpentine belt can be contaminated with fluid and then become misaligned and in this case, it needs to be replaced. In the worst case, old belts can be so worn out that they snap – If they do, power to all of the engines components will be lost. If you notice that the belt is worn you should get it replaced. Since the belt drives power to a lot of components like the AC, if not replaced, this could lead to a damaged engine and some parts in the vehicle being damaged.
Idler Pulley – like the pulley, if the idler pulleys bearings are failing, it can cause it to make noises which can be heard from the AC. Overtime, the pulley spins with the belt and it can start to wear out. Once it starts it wear out, it can cause noises which can be heard from the AC.
Compressor Clutch – the ACs compressor clutch is used to connect and disconnect drive power to the vehicle’s AC compressor shaft. The compressor clutch is meant to provide full drive power to the AC compressor or none at all – the drive power can’t be partial. The clutch compressor is a high wear item and it can wear down over time. This can cause weird noises to come out of your AC. If the compressor clutch is damaged, in some vehicles only this needs replacing. In other vehicles, the compressor clutch along with the AC compressor needs to be replaced as well.
As you can see, there are many sources in the system that could cause the AC to make noises. When you turn the AC on, it puts pressure on the engine and this increased pressure can cause clicking and rattling from components like the power steering pump pulley, loose parts and a loose hood prop can rattle under the vibrations from the AC.
Poor Maintainance – Failing to maintain your AC can result in the AC failing and having problems. You need to make sure that the components that allow the AC to function are being looked after unless they can start to fail overtime. This can cost a lot to repair so it’s best that you prevent this from happening.
If you want to avoid AC problems or other issues and save $100s of dollars that you’ll spend at the auto repair shop, you’ll need to service your vehicle often – you can use our mechanic-rated Auto Maintenance and Repair Manual to do this. It’s basically what mechanics use to go through your vehicle to check if there are any problems that need fixing. As soon as they notice the most minor problem, they’ll ask you to fork out some money even though it’s a problem you can fix yourself in minutes – the manual will teach you how to maintain your vehicle every few thousand miles and it’ll teach you how to fix minor problems that mechanics will ask you to pay for; saving you money in the long run.
A lot of our readers have the Auto Maintenance and Repair Manual printed on their garage wall and 92% of them haven’t visited the auto repair shop in the last year because they know what to do to avoid problems. All it takes is giving your vehicle a little attention every few thousand miles and you’ll never spend money at the workshop again.
Diagnosing Noises Heard from AC
There are a few different noises that you could hear from the AC that could signal trouble. Some sounds are quite normal, and others could signify that there’s a problem with one of the components above. If you find the one of these sounds is being caused by one of the failed components above, then you’ll need to get it to a repair shop and get them checked out. Down below are a few noises that could be heard from your AC that could signify that there’s a problem.
Loud Squealing or Screeching – a common sound that can be heard from the AC that could signify a problem is a squealing sound – this is a common sound that could be heard, and it can signify the serpentine belt is broken. The serpentine belt turns the pulley at the AC compressor and the compressor is engaged and disengaged by an electromagnetic clutch. This pressurizes the refrigerant lines and makes it possible for your vehicle to get cool.
Overtime, the serpentine belt can be worn down and this can cause cracks, wear and tear – a worn down serpentine belt can cause a squealing or screeching sound in your vehicle. In this case, you’ll need to get your vehicle to the mechanic so that the serpentine belt can be diagnosed – they could also diagnose failed bearing in the compressor pulley, and this can cause noises too.
Hissing Sound – another common sound that can be heard from the AC is a hissing sound – this sound is most likely to be heard when the car is turning off. In most cases, a hissing AC isn’t going to be a problem. If you’ve just turn off your car and you can hear a hissing sound coming out, it can be a sign that your car is equalizing pressure. When the AC is running, there can be a high and low pressure in the system.
Some ACs have refrigerant that moves between two separate sides that are divided by an expansion valve or orifice tube. When you turn off your car, it can cause the refrigerant to move from a high-pressure part of the AC compressor to a lower pressure part so that the pressure is equalized. If you can hear a buzzing sound rather than a hissing sound, you may need to visit the mechanic.
AC Buzzing – Another common sound that can be heard from the AC is a buzzing sound. This sound is most likely heard when you turn on your AC or when you start to accelerate. If these are the situations you heard the buzzing sound in, it could mean that you have too much refrigerant in the AC system. This is a cooling agent that’s used to create the cool air, also known as Freon.
If you’ve recently had the refrigerant topped off, excces could have entered the AC compressor intake port, and this can cause further problems. If this is the case, then the AC won’t be able to cool down your vehicle properly and it could cause damage to other components in your vehicle. In this case, you’ll need to head down to the mechanic to get it checked out. Replacing the entire air conditioner compressor can be expensive.
Knocking or Clicking Sound – a knocking or clicking sound being heard from the AC is common. Luckily if you hear this sound, you can fix the problem yourself. A knocking or clicking sound can signify that the AC components have loose mounting bolts therefore it’s not tight enough. The sound you’re hearing is the loose parts shaking when you turn on the AC.
To fix this, you’ll need to open the hood and increase the ACs intensity. You’ll need to see which parts need tightening. When you’ve found the loose areas, turn off your AC and check them out. Now, you can get a wrench and tighten the bolts, so the components are tightened. Step into your car and crank up the AC again to see if the parts are still loose. If not, you can hop back into your vehicle and you shouldn’t be able to hear the racket coming from the AC.
Rattling – another common sound you’ll hear coming from the AC is rattling. Since your engine is under a lot of pressure when you turn on the ac, the rattling sound can signify a lot of things. The rattling can signify a bad AC compressor. The AC compressor can start failing after being used for so many years and once it starts to fail, it’ll give off a rattling noise. If the compressor clutch is damaged, it can cause a rattling noise. The compressor clutch provides full drive power to the AC compressor. It also pressurizes the ac and pumps refrigerant through the lines. If this is damaged, it can cause a rattling sound to come out the AC when it;s turned on. If the idler pulleys bearings are failing, it can cause a rattling noise to come out the AC once it’s turned on.
In any of these cases, a rattling sound could signify a problem with one of the AC components and you should head down to the mechanic to get it checked it – here, they’ll be able to give you a real diagnosis and in most cases, they’re not expensive.