Signs your Car Air Conditioner Needs Repair

A car air conditioning system is an essential component that ensures you have a comfortable driving experience regardless of the weather. However, like all other mechanical parts of your car, your AC system may begin to experience wear and tear over time. If you’ve noticed that your car’s air conditioner isn’t working as well as it used to, it may be an indication of a failing AC system.

In this article, we’ll discuss three signs that your car’s air conditioning system is failing.

3 Major Signs your Car Air Conditioning system Is Failing

If you have any one of the 3 signs (or all of them) below, then there is a huge possibility your car air conditioning system needs repair.

Car Air Con loosing cooling

1. Loss in the cooling capability of the system

The primary function of your car’s air conditioning system is to cool the cabin and the most obvious symptom that a vehicle’s air conditioning might have issues is that there will be a noticeable loss in the overall cooling capacity of the AC system. You may notice that the air is not blowing as cold as it was before or is not blowing cold air at all.

There could be several reasons why your air conditioning system is not functioning properly.

  • Refrigerant leak: If your air conditioning system is low on refrigerant, it will not be able to produce cold air. A refrigerant leak is the most common cause of low refrigerant levels. As refrigerant leaks are not normal, the system must be checked for leaks and repaired before being refilled with refrigerant.
  • Faulty compressor: The compressor is the heart of the air conditioning system, and if it is not functioning correctly, it will not be able to compress the refrigerant properly, which will result in a loss of cooling. Signs of a faulty compressor include strange noises or a noticeable decrease in cooling performance.
  • Clogged condenser: The condenser is responsible for removing heat from the refrigerant, and if it becomes clogged with dirt or debris, it will not be able to function correctly. This will cause the air conditioning system to produce warm air instead of cold air.
  • Blocked orifice tube/expansion valve: The orifice tube/expansion valve regulates the flow of refrigerant through the air conditioning system. If it becomes blocked, it will restrict the flow of refrigerant and reduce the cooling capacity of the system.
  • Malfunctioning evaporator: The evaporator is responsible for removing heat and moisture from the air in the passenger compartment. If it is not working correctly, it will not be able to remove enough heat, which will result in a loss of cooling.
  • Electrical issues: Faulty wiring or electrical components can also cause a loss of cooling in the air conditioning system. This could include issues with the thermostat, relays, or switches, among others.

If you are experiencing a loss of cooling in your car’s air conditioning system, it is important to have a qualified car air conditioning technician diagnose the issue. They will be able to identify the root cause of the problem and recommend the necessary repairs to restore your system’s cooling performance.

Strange noises from Car AC

2. You hear strange noises from the system

Strange noises coming from under your hood are always a cause for alarm. When you turn on your A/C, you should hear the fan blowing cool air, but if you hear a banging, hissing, or rattling sound, something is wrong.

These three noises could be directly related to your air conditioning system.

  • Hissing sound: If you hear a hissing sound coming from your car’s air conditioning system, it could be a sign of a refrigerant leak. The hissing sound is usually caused by the refrigerant escaping from the system, which can happen due to a leak in the hoses or fittings. It’s important to have the system checked and repaired by a professional technician to prevent further damage and ensure proper functioning.
  • Grinding noise: A grinding noise coming from your car’s air conditioning system could indicate a problem with the compressor. The compressor is responsible for compressing the refrigerant and circulating it through the system. If it starts to fail, it can produce a grinding noise. If you hear this noise, it’s important to have the system checked as soon as possible to prevent further damage and costly repairs.
  • Squealing noise: A squealing noise could indicate a problem with the belt that drives the air conditioning compressor. The belt may have become loose or worn out, causing it to slip and produce a high-pitched squealing noise. If you hear this noise, it’s important to have the belt replaced as soon as possible to prevent further damage and ensure the proper functioning of the system.

If you hear any strange noises coming from your car’s air conditioning system, it’s best to have it inspected by a car air conditioning professional as soon as possible.

Car Air Con emitting bad smells

3. Bad Smell

If you start noticing strange smells coming from the air conditioning vents, it could be a sign that something is wrong. Let’s explore some of the different bad smells that you might notice and what they could mean for the health of your car’s air conditioning system.

  • Musty or Moldy Smell: This type of smell is usually caused by mold or mildew growing in the evaporator core, which is the component responsible for cooling the air that comes out of your vents. A clogged or dirty cabin air filter can also contribute to this smell.
  • Burnt Smell: A burnt smell could be a sign of a failing compressor or clutch, which could potentially lead to a costly repair if not addressed promptly. It could also be a sign of electrical problems or a loose belt.
  • Rotten Egg Smell: If you notice a rotten egg smell, it could be due to a refrigerant leak, which could be harmful to both you and the environment. It’s important to have the leak repaired and the refrigerant properly disposed of as soon as possible.
  • Chemical Smell: A chemical smell could indicate a leak in the cooling system or the presence of a harmful substance. This smell should be taken seriously and addressed immediately by a professional.
  • Sweet Smell: A sweet smell may be caused by a coolant leak, which can lead to engine overheating and other serious problems. If you notice a sweet smell, it’s important to have your car checked by a mechanic as soon as possible.

If you notice a bad smell coming from your car’s air conditioning system, it’s best to have it inspected by a car air conditioning specialist.

What to do if you notice these major signs?

If you notice any of the above-mentioned signs that your car’s air conditioner is failing, it is important to take immediate action. Here are a few things you can do:

  1. Get it diagnosed by a professional: The first and foremost thing you should do is get your car’s air conditioner diagnosed by a professional. A qualified technician can identify the root cause of the problem and provide the necessary repairs or replacements.
  2. Check for leaks: One of the most common reasons for a failing air conditioner is leaks in the system. If you notice a loss of cooling, it is important to check for leaks in the system. You can do this by using a leak detection kit or by taking your car to a professional technician.
  3. Clean or replace the cabin air filter: If you notice a bad smell coming from your air conditioner, it could be due to a dirty or clogged cabin air filter. This filter is responsible for removing pollutants, allergens, and other contaminants from the air before it enters your car. A dirty filter can cause unpleasant odors and affect the performance of your air conditioner. You can either clean or replace the filter to solve the problem.
  4. Avoid DIY repairs: It may be tempting to try and fix the problem yourself, but it is best to avoid DIY repairs. Car air conditioning systems are complex and require specialized knowledge and tools to repair. Attempting to fix the problem yourself could cause further damage and end up costing you more in the long run.


A failing car air conditioning system can be a frustrating experience, particularly during the hot summer months. It’s essential to have your car’s AC system inspected regularly by a professional mechanic to ensure that it’s functioning correctly.

If you’ve noticed any of the signs mentioned in this article, it’s best to have your car’s AC system inspected by a car air conditioning expert as soon as possible to prevent further damage and costly repairs down the road.


12 Replies to “3 Signs your Car Air Conditioner needs repair”

  1. I like that you point out that one sign that your AC needs to be serviced is that there could be a rattling noise when you turn it on. I can see why this would be an easy way of noticing that something is wrong. The AC in my brother’s car stopped working last summer and he hasn’t gotten it repaired since then. I’ll have to ask him if he heard any rattling before it went out.

    1. Jack Frost 7 years ago

      Thanks, Scott, we appreciate you stopping by and leaving a comment.

      Yes forward this post onto him and have him check if any of these issues are occurring. If so he will need a potential Car AC repairs, including a condenser replacement

  2. Devon Horn 7 years ago

    I like the portion mostly that represents the signs by which one can know that the air conditioning system in his car is not working properly. 2-3 times I had also heard some strange noises coming from my car A/C but I had ignored It due to which I spent a lot in repairing my car A/C later on. So, it is always better to take proper car of car air conditioning system in order to remain cool and comfortable while driving especially in hot summer days. On a final note I can say that your blog is very help for me and I am sure it will help many more in near future. That is why I simply want to say thank you for sharing this.

  3. Well, owning a car requires a lot of care and love. The air conditioning system being an integral part of car should be properly inspected and maintained well. So, if someone notices any kind of trouble or anything that may seem not to be functioning well, then make sure to get it serviced as soon as possible. I like your blog very much as it is dealt with some warning signs related to car ac failure. It will surely help to address the cause of the problem. I would like to suggest that scheduled maintenance is the best way to keep the car and car ac in well-running condition.

  4. Saara Caitrona 7 years ago

    Yes, when you uses your air condition while in driving, you need to remember that heat and moisture from surrounded air in the car is removed through use of energy. The compressor compress the gas once it is inside the car pump. The most noticeable signs of a/c to be replaced is when there will be significant loss in the overall cooling capability in the air conditioner system. If you hear a noise it might be a problem with your belt. It is therefore optional for you to check the condition before air condition get completely out of control. If you notice bad smell , then it might be a case of mold that is growing inside the system. Timely fix the a/c is essential and therefore do notice the symptoms in a/c and prevent any mishap to happen. Nice blog to appreciate.

  5. Sharon Lee 7 years ago

    Here, you have delivered a useful info based on warning signs behind car ac failure. Well, in this regard I can say that car’s air conditioning system is one which keeps the car and its occupants cool during the hot summer. That is the reason why, it has become a common feature in many modern cars. But it is quite unfortunate to say that many people overlook their car’s air conditioning system because they think that their car’s air conditioning system is only useful in summer. But this is not the real scenario, as it not only gives cool air in summer but also delivers dehumidified air in winter and makes the journey easy and comfortable. So, don’t ignore the warning signs, rather it must be inspected on a regular basis by taking the help of an expert,o keep it in good working condition.

  6. I have noticed that my AC was not cooling so well, then I went to have it refilled, it cools better now but cuts sometimes. There are times when it blows cold air all day and other times I have to turn off the ac and back on before it works. But is it necessary to empty the old air before adding new gas to the compressor?

    1. Jack Frost 6 years ago

      Diagnosing intermittent problems vary depending on the make and model of your vehicle, yes the system must be decommissioned completely first then hydrogen/nitrogen pressure tested.

      If it passes these tests it is then Gassed with the specified weight of gas, simply Re-Gassing the a/c system won’t fix an intermittent problem.

      It could be a faulty clutch relay, clutch coil or clutch fault itself.

      If it a later model European car it is more than likely a faulty control valve in the compressor.

      Please confirm your booking ASAP as we are booking up very quickly in this warm weather and are unable to hold bookings without confirmation.



  7. It doesn’t matter what type of vehicle you drive, at some point in time your car’s going to need some type of repair. Fantastic article.

  8. The air coming out of my car’s vent smells bad and I didn’t know that there were so many things to look at with maintenance! So, I’m going to hire a professional technician to take a look at it before summer arrives.

  9. Kate Hansen 5 years ago

    I like how you said that if you notice a bad smell when you turn your AC on your system may be failing. My AC has been having a bad smell every time I turn it on. I’ll make sure to keep this in mind while I search for an auto shop repair service.

  10. Rolly Cafuir 4 years ago

    When stuck in traffic for 20 or more mins, coldness diminishes until none, sometimes the engine stops, then restart it what’s seems to be the problem?

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