Air Conditioner Makes Loud Noise (When Starting Or Off)

If your air conditioner makes loud noise when starting or after shut off, then this guide will help you figure out the cause and solution to this problem.

Your air conditioner gets a lot of use during the hottest months of the year. You rely on it to keep your home as comfortable as possible. If your air conditioner makes loud noise when it’s turned on, then you might be a bit concerned. Is this normal, or is it something that you need to be worried about?

The answer is a little bit complicated, and it’s tough to determine the problem without hearing what’s going on or inspecting the unit. Some air conditioner noises are going to be perfectly normal. There are many air conditioning units that will make a bit of noise when they’re running. You have to be able to differentiate an unusual air conditioner noise from a typical operational noise.

Scream Noises

If the loud noise that you’re hearing is a high-pitched sort of “scream,” then it’s definitely a problem. An air conditioner will make this type of noise when it turns on, and it might even stop after several seconds. This isn’t normal, and it’s likely occurring due to the compressor going out. You’re going to want to replace the compressor right away, and you might need to call in a professional to do the repair job, depending on what skills you have.

Squealing Noises

Squealing noises while the AC unit is turned on will also mean that you need to repair or replace or something. You see, a squealing noise is typically going to be an indication that your AC unit has a worn-down belt or that the belt is misaligned in some way. You can look inside of the unit to inspect this, and you might be able to fix it by realigning the belt. If this doesn’t work and the belt looks worn, then it will need to be replaced to get rid of the noise.

Screeching and Gurgling Noises

Other noises to be concerned about include screeching metal-on-metal noises and gurgling noises. A screeching noise is an indication that your fan motor bearings are not working right, and the motor is likely going to need to be replaced. The gurgling noises are a sign that your AC unit has a refrigerant leak somewhere. You can call in an air conditioning specialist to get things fixed up fast.

Air Conditioner Makes Clicking Noises

Clicking noises while the AC unit is running will also be concerning, but it won’t be nearly as big of a deal. If you hear clicking noises coming from the outside of the unit while it is running, then that means there is an obstruction of some kind. It could be a nest or some leaves getting in the way of the unit operating as it should. You can simply go outside and remove the obstruction to get things back to working normally.

Banging Noises

Banging noises will certainly startle you but they are often simply being caused by something obstructing your fan. It’s possible that a stick or something else has gotten itself wedged inside or near the protective cage that is around the fan. If you go outside and check things out, you should be able to see what’s going on. Simply removing the obstruction should be enough to get the banging noises to stop.

Air Conditioner Makes Loud Noise After Shut Off

There are actually a few reasons that your air conditioner might make loud noises after it has been shut off. If your air conditioner is making these noises immediately after it has been shut off, then it can be an indication of a few different things. To figure out the problem, you’re going to need to be able to tell if the noise is coming from the inside or the outside. With this information in hand, you’ll be able to narrow the causes down to some likely suspects.

If the noise is coming from inside, then there is a good chance that you have an air filter problem. Sometimes the air filter will slam against the grill of your vents. This can happen when your air filter is too dirty. It can also occur when your air filter is too restrictive and doesn’t allow enough air to flow through.

Some of these noises can also happen due to problems with your fan. If your fan is loose in some way, then it could be banging up against something. The fan could be going off-balance when it starts to slow down, and that is where the noise is coming from. This isn’t uncommon at all and it should be an easy fix.

Noises that are coming from the outside are similar. It could be a sign of a compressor problem that is occurring due to a broken spring. The broken spring might be causing the pump to bump up against something. It also could be caused by a fan on the outside.

Making Pulsating Noise

Pulsating noises can actually be tough to figure out. The problem is that pulsating could be caused by a number of different problems. For instance, you could be hearing a pulsating noise due to loose parts in the air conditioner. It could also be caused by fan blades being out of balance, or you might even just need to have your air filter cleaned out.

A really bad pulsating noise could be an indication that you’re dealing with compressor issues. Some people have reported that having dirty coils outside can be the culprit. You might need to try multiple things to get this problem taken care of. Many people simply decide to call the air conditioning specialists to figure this one out.

Air Conditioner Makes Loud Buzzing Noise

Loud buzzing noises coming from your air conditioning unit can be very startling. These can occur for a number of different reasons. Your blower could be going bad, or it might be unbalanced in some way. Noises like this can also be attributed to loose parts moving around inside the AC unit.

Determining exactly what is causing a loud buzzing noise might not always be easy. You could fix things by tightening up a loose fan, or you might be at a loss as to what is wrong. If you’re left scratching your head, then it’s a good idea to consider calling in professionals to take a look at things. They’ll be able to determine the cause of the loud buzzing noise so that you can get things back to normal.


There are various potential causes for your loud air conditioning noises. Hopefully, the above information will be able to help you to get things figured out so that you can fix the problem. If you follow the advice that has been listed, then you should be able to get things back to normal. It’s also possible that you might find out that everything is fine.

Remember that some air conditioning units will be a bit louder than others. Pulsating noises and loud buzzing noises definitely aren’t normal, though. Take the time to assess the situation to see what you’re dealing with. It might be good to call in an air conditioning specialist to look at your unit to get things back to normal.

Once your issues have been sorted out, you’ll be able to simply focus on getting through the summer. The heat of the summer doesn’t have to get you down when your air conditioner is working properly. These noises that you have been hearing are concerning, but they can be fixed. Don’t hesitate to call professionals if you’re in need.