Squealing Noise When AC is Turned On (Here is why)

If you have ever heard unusual sounds as you start your Car? Do you have some clue how some of your Car’s air conditioning system is squealing as well as how to solve it? When you notice shrieking sounds whenever you start on the car air conditioner, it indicates that your compressors or belt is malfunctioning.

A malfunctioning ac unit compressor or a damaged belt would not affect the engine’s general performance, but it will prevent cold air from entering the cabin. Screeching sounds are an added benefit. “You could have a cracked or broken AC belt, a damaged AC compressor clutch, or a faulty car air conditioner compressor pulleys and bearing if the vehicle AC begins screaming as quickly as users switch it on.

Reasons for Squealing Noise of AC:

When you switch on the air conditioning on your automobile, does it produce a screaming noise? You’re not alone if this happens to you. It is the most common “strange car sound” reported by consumers. A worn-out serpentine belt is the most common source of screeching car air conditioner noise.

The serpentine belt is a long, wrap-around belt that keeps many essential parts of your car running smoothly, including the power steering pump, air pump, water pump, alternator, and, of course, your air conditioner.

Serpentine belts should last between 50,000 and 100,000 miles if tensioned and appropriately serviced. These rugged, relentless belts, on the other hand, need to be replaced now and again. Fill a spray bottle halfway with water and sprinkle the serpentine belt to examine whether the squealing noises coming from your Car’s air conditioning are coming from it.

  • A loosened or damaged air conditioning compressor belt is the most common cause of these noises. When the air conditioner is turned on, the compressor kicks in.
  • The engine and the drive belt that spins the compressor are both stressed due to this.
  • The belt can slide on the compressor pulley and generate a loud screech if slack or worn.

Malfunctioning AC compressor Clutch:

Your air conditioner will not blow cold air and will create a squealing noise as it tries to engage if the compressor clutch is defective. The AC compressor clutch is a critical component of your vehicle’s air conditioning system.

This component is responsible for pressurizing the entire air conditioning system and pushing the refrigerated air through the cooling system. The ac compressor clutch cycles on and off due to these two critical functions, and it eventually wears down and breaks.

Reasons for Car AC Compressor Clutch Failure?

You’ll hear a screaming noise and no cold air if you have a broken AC compressor clutch. The AC compressor clutch might fail for a variety of reasons:

The Low-Cost Refrigerant of AC:

It is the reason for the failure of the clutch, and that’s why the clutch is not engaging or creating screeching noises as it tries to engage in low amounts of AC refrigerant.  Sensors in the air conditioning system check to see if the system has appropriate pressure.

The AC clutch does not undertake if there is a stress problem. If you’re low on refrigerant, your compressor will have to work twice as hard to cool the air.

Components that are Worn Out:

Bearings, brackets, and tensioners are part of the AC compressor clutch. Most of us drive with the air conditioner on practically all of the time, which puts a strain on the AC clutch.

These components will wear down over time, and the ac compressor clutch will fail. Dust, grease, and moisture build-up on the ac compressor clutch over time, causing it to fall.

Parts Not Installed Properly:

As previously said, the ac compressor clutch includes many components. When an AC professional makes a mistake, they may install some minor components incorrectly.

A bearing that has fit poorly will not exhibit any signs of failure immediately away, but it will eventually fail. Human mistakes occur in every sector, and we can do little to prevent them.

Weak AC Compressor Pulley and Bearing:

When the engine is running, the AC compressor pulley link by a drive belt and rotates at all times. While turning, a defective ac compressor pulley and bearing might generate screeching noises. Although the AC compressor pulley spins, the AC compressor shaft does not.

When the air conditioner switches on, the compressor shaft revolves. Since it rotates as the engine starts, this component can wear down over time and make screaming noises. Some factors contribute to the premature failure of the ac compressor pulley and bearing.

Reasons for Compressor Bearings and Pulleys Fail?

You can hear a squealing noise from the engine when the ac compressor pulley and bearing failure. Here are a few of the most common causes of ac compressor pulley and bearing failure:

Excessive Heat:

It is the number one enemy of all automotive air conditioning components. Extreme heat produces while the AC compressor pulley rotates with the bearing, causing damage to the pulley and bearing seal.

The revolution creates heat that can exceed 1200 degrees Fahrenheit. This heat will dry out the grease in the bearing, which will result in a squealing noise.

Compressor Shaft Seal Leakage:

When the compressor shaft seal leaks, it goes into the bearing grease and contaminates it. Bearing grease and shaft seal grease have different characteristics. The grease inside the bearing would be unable to lubricate it as it should, failing.

Refrigerant Leaks:

If the ac refrigerant lines break, the refrigerant leaks. There is another issue in addition to the low refrigerant level. In this condition, the compressor will not work.

Also Read: Humming Noise in Car Getting Louder with Speed (Here is why)

AC Belt Is Broken:

The AC belt links the AC compressor clutch to the engine crankshaft when you activate your Car, allowing the AC compressor clutch to rotate. A broken or worn-out AC belt will make screaming noises when you turn on the air conditioner.

There are two kinds of car Ac belts, V-Belt and Serpentine belts. The form of the two is what distinguishes them. If you hear squealing noises as soon as you turn on your air conditioner, you may change your car Ac belts.

How to solve the Problem of AC squealing Noises?

The air conditioning system is based on the pulley and bearing of the AC compressor. They begin to rotate as soon as the engine switch on. When the user turns on the air conditioner, the compressor pulley and bearing and the compressor clutch begin to spin, and cold air begins to flow. Here is how to replace an ac compressor pulley and to bear if they are affected:

Remove or Change the Pulley and Bearing:

The compressor is located on the back seat of the engine bay. By removing the passenger side wheel, you can access it from the top or side. To remove the compressor clutch, you will need a 6mm socket. Remove it when disconnected.

Rotate the pulley:

Rotate the pulley to see if it works. If the compressor pulley does not turn on, the problem is with the compressor. Using a hammer or two-point hammer, remove the compressor pulley. If the bearing is safe, you will need to replace the entire compressor pulley and replace it with a new one. The compressor pulley has a bearing inside it.

Replace the bearing:

You can replace a bearing if it is faulty. You’ll need a socket and a hammer to remove it. Replace the bearing with a new one. Once you remove it after installation, test the pulley to see if it fixes well.

Fix the broken belt:

The AC belt should be the first thing you look for. The ac compressor belt is present over the compressor.

Check the type of AC belt you have:

As previously stated, the AC belt can be either a v-belt or a serpentine belt. Their size is what separates them. With only one rib, the v belt is slimmer. There are multiple ribs in the serpentine belt. With a wrench, unscrew the bolt on the AC belt tensioner. Depending on the Car, the ac belt tensioner can loosen by rotating clockwise or counter clockwise.

Remove the AC Belt:

You should be able to remove the belt with your bare hands after loosening the ac belt tensioner. Ensure the pulleys are clean and free of any rubber from the belt. Tighten the ac belt tensioner after installing the replacement belt. You can tighten the ac belt tensioner once you’ve placed the new ac belt on the rollers.

Repair the Compressor clutch:

It would be best if you disconnected a connector on the magnetic coil of the compressor. The AC clutch should have a 6mm socket in the centre that you will need to remove. Disconnect the clutch and pull it out.

Make sure the spacers on the shaft don’t get lost because they gap the clutch, and you’ll need them later. You will see a snap ring on the shaft; remove it and slide it off. Clean all parts, then start the installation.

Here is a great video on how can you repair your AC Clutch and diagnose noise,

But I recommend you guys to take your car to the nearby Mechanic and get the issues sorted out.

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