Air Conditioner Making Pulsating Noise: 7 Causes & Quick DIY Fixes

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When your air conditioner isn’t working right, it might make loud and strange noises. If you hear clicking, clanking, or banging sounds, you ought to have them looked at right away.
Not only are these noises annoying, but if you don’t fix them, they could lead to expensive repairs.
If your air conditioner’s outdoor compressor is making a pulsing sound, it probably isn’t a big deal, but you should still check it out.
Some pulsing sounds might be acceptable, but once the sound is loud enough such that it can be heard from inside house, it could mean that a loose component or panel is causing the shaking.
The motor’s fan blade and the coil fan are two parts that could be loose.In some cases, the noise could be coming from the fan motor, and in this case, it needs to be replaced.

1. Faulty Blower Wheel

The blower wheel is a key component in your AC unit that helps to move air through the system. The wheel is attached to the motor and spins as the motor runs. This action helps to create airflow within the unit, which ultimately cools down your home or office.
If the blower wheel becomes damaged, it can cause your AC unit to work less efficiently and may even lead to complete failure and could even cause pulsating noises. Replacing a damaged or worn out blower wheel is essential to keeping your AC unit running properly.

2. Damaged Bearing

The air conditioner bearing is a very important part of the air conditioner. It helps to keep the air conditioner running smoothly and quietly. Without it, the air conditioner would be very loud and would not work properly.
Additionally, it helps to prolong the life of the air conditioner by reducing wear and tear on the compressor and other parts of the system.
An air conditioner bearing can also improve energy efficiency by reducing friction between moving parts.
This can lead to lower energy bills for customers who use their air conditioners regularly. In some cases, it can also help to improve the overall performance of the air conditioner.

3. Dirty Filter

An air conditioner filter is a device which is used to filter out impurities from the air. It is typically made of paper or cloth and is placed in the air conditioner unit.
The purpose of the air conditioner filter is to improve the quality of the air inside the room by removing dust, pollen, and other allergens.
One of the most common reasons for a pulsating noise coming from your air conditioner is a dirty filter. A dirty or clogged filter will restrict airflow, causing the unit to work harder and run longer in order to maintain the set temperature. This can cause the unit to vibrate and emit a pulsating noise.
A clean air filter not only prevents your AC unit from making strange noises, but also improves efficiency, saves money on energy bills, and extends the lifespan of your unit.

4. Low Refrigerant Pressure

Refrigerant is a substance used in refrigeration and air conditioning systems to transfer heat from one area to another. It can be either a gas or a liquid, and is typically found in aerosol cans or in pressurized cylinders.
When used in an air conditioner, the refrigerant absorbs heat from the inside of the fridge and transfers it to the outside air. In a refrigerator, the reverse happens – heat is transferred from the outside air into the fridge, cooling it down.
Low refrigerant levels can cause your air conditioner’s compressor to make a pulsating noise. The refrigerant is what helps your AC unit cool the air, so when it’s low, the unit has to work harder, which can lead to a pulsating noise. You’ll likely need a professional to recharge your system with refrigerant.

5. Faulty Compressor

The air conditioner compressor is a vital component of any AC system. The compressor is responsible for circulating refrigerant throughout the AC system, and if it’s not working properly, it can cause the entire system to operate inefficiently

If your air conditioner is making a pulsating noise, it could be due to a faulty compressor. In some cases, a faulty compressor can also cause the AC unit to overheat, which can damage other components and lead to a total system breakdown.

Air Conditioner Noises and What They Mean

Other types of air conditioner noises should be a cause for alarm. Let’s have a look at these noise types.


Like pulsating, clanking is a sign of a loose part or a misaligned AC part.

Some parts inside the air conditioner’s sealed unit have likely failed, and the compressor could be loose hence requiring a replacement.

Clanking noises could also mean that the outdoor or indoor blower fan and the blades are out of balance.

In such a scenario, the problem could only worsen, and worst-case scenarios create more significant problems.

Air Conditioner Making Pulsating Noise


Like any other appliance or tool, banging noises are usually an indicator of a broken or loose part- in this case, possibly a crankshaft, piston pin, or a connecting rod inside the air conditioning compressor.

In other cases, it could be a sign of an imbalanced indoor blower.

In some extreme cases, banging noises could be an indicator that the compressor needs replacement.

Buzzing Noises

There are different causes of buzzing noises in an air conditioner. They include:

  • Debris in the outdoor or indoor unit
  • Loose parts
  • Fan motor loose
  • Loose blades
  • Condenser coils need cleaning
  • The air filter needs replacement
  • Blower out of balance or going bad
  • Refrigerant leaks

If you note that the air conditioner usually operates outside but doesn’t cool your room, then the biggest culprit, in this case, is a refrigerant leak.

This could be accompanied by some weird noises depending on the leak location.

Clicking Noises

There are some normal clicking noises, such as when switching on and shutting down the air conditioner.

However, a constant and unending clicking noise is something that should make you worry.

Clicking noise could be a sign of a failing thermostat or even a defective control.

Additionally, there are lots of electrical components in your AC, and so it’s always important to pay attention even to the slightest electrical issue as soon as possible before they escalate to bigger issues.


Rattling noise could be a sign of deteriorating air conditioner and loosening parts.

On the other hand, it could be a sign that leaves or twigs have clogged the system.

Additionally, the electrical contractor in the AC can also make chattering noises which could damage other elements, including the compressor, if allowed to operate for long.

The fan also produces rattling noises when loose.

In this case, the first thing you should do is to inspect for any loose bolts or screws in the unit casing, change the indoor filter, and clean the condenser coils.


Humming noise isn’t something serious, but it’s an indicator of something wrong inside the air conditioner.

Loose refrigerant piping or parts can be a cause for humming noise, and when left unchecked, it could result in some severe problems.

In most cases, buzzing or humming noises are signals of electrical problems.

If the AC compressor only hums and doesn’t start, then the problem could be with the motor system, even though loose wiring can also be the cause.

Air Conditioner Making Pulsating Noise


Does your air conditioner sound like a helicopter?

If that’s the case, you could face a series of mechanical problems either with the outdoor or the indoor blower.

In most cases, whirring noises result from bad bearings from the indoor blower fan motor or a mechanical problem in the outdoor unit or indoor blower unit.

When the fan blades become loose or damaged belts in the system, whirring noise can occur.

In rare cases, debris or piece of paper can get trapped in the outdoor fan unit or indoor blower fan, causing whirring noises.

Screaming Noises

High pitched noises could be mean something wrong that needs professional fix immediately.

If you hear a screaming or high-pitched noise, I recommend you switch off the unit and call a professional immediately.

This is because refrigerant leak causes this sound and can damage your AC and cause serious health problems. (Source)

Screaming noise could also be an indicator of high internal pressure in the compressor, which can also be dangerous.

If your AC turns off by itself, then you shouldn’t panic as it’s an indicator that a sensor is doing its job in protecting you from a possibly hazardous situation.

On Air Conditioner Making Pulsating Noise

Air conditioner making pulsating noise isn’t a major cause of concern but should warrant professional inspection.

Summers are hot, and you need a well-functioning air conditioning unit to welcome the hot days.

An air conditioner isn’t a luxury but rather a necessity, and when it’s making noises, it needs to be fixed since it’s not only your comfort that’s at stake.

When the temperatures in your home reach whole new levels, your emotional and mental well-being significantly plummets just as your physical comfort.

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