7 Low Freon Symptoms in Car

Find out if you’re overpaying on car insurance using our cost calculator! Save money by comparing quotes from over 30 of Canada’s top insurance providers!

The best part? It’s FREE!

low freon symptoms in car

If you’re experiencing problems with your air conditioning, one of the first things you should check is the freon level in your system.

Low freon levels can cause various symptoms, including poor cooling performance, strange noises coming from the AC unit, and ice formation in the vicinity of the compressor.

In this article, we’ll discuss what causes low freon levels in cars and how to recharge a car’s air conditioning system if necessary.

What is Freon?

When it comes to your car’s air conditioning system, there are a few things you should know. For starters, the AC system is filled with a refrigerant called Freon. Freon is what makes the air cold when it blows out of the vents.

Freon is a trading name for a group of chlorofluorocarbons (CFC) chemicals used as refrigerants, solvents, and aerosol propellants. Freon is used in air conditioners, refrigerators, aerosol cans, and Styrofoam. It is also used as a cleaning agent for electronic equipment.

In the early 21st century, the production of Freon was phased out because of its contribution to ozone depletion. Freon belongs to a group of chemicals called halocarbons.

Halocarbons are compounds that contain carbon and one or more other halogen elements such as fluorine, chlorine, bromine, or iodine. Freon molecules contain carbon, hydrogen, chlorine, and fluorine atoms. The most common Freon compounds are R12, R134, and R22.

How Does a Car’s Air Conditioning System Work?

A car’s air conditioning system works by removing heat and moisture from the vehicle’s cabin. The AC system does this by circulating a refrigerant through a closed loop system of evaporator and condenser coils.

As the refrigerant passes through the evaporator coils, it absorbs heat from the cabin air, which causes it to vaporize. The now-vaporized refrigerant then passes through the compressor, where it is pressurized and routed to the condenser coils.

As the refrigerant passes through the condenser coils, it releases its heat to the outside air, causing it to condense back into a liquid state. The now-liquid Freon is routed back to the evaporator coils to start the process over again.

Symptoms of Low Freon Levels

If you think you may have a Freon leak, there are several symptoms you can look for:

  1. AC Blowing Room Temperature Air
  2. Sweet Smell Inside Cabin
  3. Visible Refrigerant Leaks
  4. AC Clutch Not Engaging
  5. Ice Formed Around Compressor
  6. Cold Air is Not Cold Enough
  7. Strange Noise From Compressor

For better understanding, let us offer an in-depth look into each of these symptoms:

1. AC Blowing Room Temperature Air:

If your AC suddenly blows warm air, it could be a sign that your system is low on Freon. When the refrigerant level gets too low, the compressor can’t pressurize the Freon properly, which prevents it from absorbing heat from the cabin air.

As a result, the air that blows out of the vents will be the same temperature as the ambient air outside. Thus, the car cabin won’t be any cooler than outside. This problem reveals itself more quickly on hot days.

2. Sweet Smell Inside Cabin:

If you notice a sweet smell coming from the AC vents, it could be a sign of Freon leakage. The sweet smell is caused by the evaporator coils leaking Freon into the cabin.

When Freon leaks into the cabin, it can cause respiratory problems and other health issues. Leaking Freon can also damage the AC system itself. When too much Freon leaks out, it can cause the compressor to fail.

Compressor failure is costly to repair and can lead to other problems down the road. Thus, it’s important to address this car ac smell as soon as possible.

3. Visible Refrigerant Leaks:

One of the most obvious signs of a low freon is a visible refrigerant leak. If you see a pool of liquid under your car, it could be Freon. Freon is stored in the AC system as a pressurized gas.

If there’s a leak in the system, the Freon will escape as a gas. However, if the leak is severe, the Freon can turn into a liquid before it escapes from the system.

Refrigerant leaks can be caused by several factors, such as loose fittings, damaged hoses, or cracks in the evaporator coils.

Leaking Freon not only damages the AC system but also harms the environment. When Freon escapes into the atmosphere, it contributes to ozone depletion.

4. AC Clutch Not Engaging:

If the AC clutch is not engaging, it could be a sign of low Freon levels. The AC clutch is a device that engages the compressor when the AC system is turned on.

When the Freon level gets too low, the compressor can’t build enough pressure to engage the clutch. As a result, the AC system won’t work properly.

This problem can also be caused by other factors, such as a faulty AC switch or a damaged compressor. Thus, it’s best to have this problem diagnosed by a professional.

5. Ice Formed Around Compressor:

Another symptom of low Freon levels is ice forming around the compressor. When the Freon level gets too low, the evaporator coils can’t absorb enough heat from the cabin air.

As a result, the moisture in the air can condense on the coils and freeze. This problem is more likely to occur on cold days. If you notice this symptom, you should take your car to a mechanic as soon as possible.

6. Cold Air is Not Cold Enough:

If you notice that the cold air from your AC is not as cold as it used to be, it could be a sign of low Freon levels. When the Freon level gets too low, the AC system can’t cool the cabin air properly. As a result, the air that blows out of the vents will be warmer than usual.

One possible reason for this is that the low Freon level may be causing the compressor to work less efficiently. When the compressor is not working properly, it can’t cool the air as effectively, which leads to warmer air coming out of the AC unit. Due to this car overheats when the ac is on.

7. Strange Noise From Compressor:

Last but not least, a strange noise from the compressor is another symptom of low Freon levels. When the Freon level gets too low, the compressor can’t pressurize the Freon properly. As a result, the compressor will make a strange noise as it tries to pressurize Freon.

Secondly, low freon will cause the compressor to work harder than usual, leading to rattling noise. If you notice either of these symptoms, you should take your car to a mechanic as soon as possible.

Why Do Freon Levels Drop in a Car?

There are several reasons why your car’s air conditioning system may have low freon levels.

A common reason is simply that the system is leaking somewhere and needs to be recharged. Sometimes the compressor isn’t functioning properly, which can cause Freon to leak out.

Another potential issue is that the system wasn’t properly sealed during manufacturing, which can allow Freon to escape over time. Or, if your car has been sitting for a long period (months or years), the Freon may have slowly leaked out through seals and gaskets.

How to Recharge Car’s Air Conditioning System?

If your vehicle’s air conditioning system is low on Freon, you’ll need to recharge it. This process is relatively simple and can be done at home with a few tools.

Take Precautions:

Refrigerants can be an environmental hazard. You should take proper precautions when handling them. Be sure to wear gloves, goggles, and a mask to avoid coming into contact with the Freon. Inhaling Freon can be harmful, so it’s important to protect yourself.

Choosing the Correct Refrigerant:

The cars produced after 2015 use R-1234YF refrigerant. If your car was produced before 2015, it likely uses R-134A refrigerant. Be sure to check your car’s owner manual to find out which type of refrigerant it requires.

Locating the Low and High Side Service Ports:

The first step is to locate the low and high-side service ports. These are located on the AC lines that connect to the compressor. The low side port will be larger than the high side port. Once you’ve located the ports, use a clean rag to clean off any dirt or debris that may be blocking them.

Connect Recharge Port and Valve to Refrigerant Canister:

Next, you’ll need to connect the recharge port and valve to the refrigerant canister. Make sure that the canister is in an upright position so that the Freon doesn’t spill out.

Blow Air Out of the Hose:

Before you start the recharge process, you’ll need to blow hot air out of the hose. This will help to prevent Freon from leaking out when you begin the recharge process.

Connect Pressurized Refrigerant Can to Low-Pressure Side:

Once you’ve blown air out of the hose, you can connect the canister of refrigerant to the low-pressure side. Be sure that the valve on the canister is closed before you connect it. Now it’s time to open the valve on the refrigerant canister and allow Freon to enter the AC system.

Connect Pressure Gauges:

The next step is to connect the pressure gauges to the low and high-pressure sides. This will help you to monitor the Freon levels as you’re recharging the system. You can easily find pressure gauges at any auto parts store.

Turn on the AC to Blow Cool Air:

Now it’s time to turn on the AC and allow cool air to blow out. This will help you to identify any leaks in the system. If you see Freon leaking from any of the hoses, you’ll need to repair the leak before continuing.

Power Up the Compressor if AC Doesn’t Work:

When you are trying to turn on the AC compressor after recharging the freon, it is possible that the refrigerant hasn’t reached the compressor. In this case, you can power up the compressor by jumping the low-pressure switch with a wire.

To do this, simply locate the low-pressure switch, which is usually located near the firewall. Once you’ve found it, use a wire to jump the two terminals on the switch. Directly connect battery voltage to one terminal and ground the other. This will bypass the switch and allow the compressor to turn on.

Check Readings on Pressure Gauge:

As you’re recharging the system, keep an eye on the pressure gauges. You’ll want to stop adding Freon when the low-side pressure reaches 30 psi, and the high-side pressure reaches 200 psi.

Turn Off the Valve and Disconnect the Hoses:

Once you’ve reached the correct Freon levels, you can remove the recharge hose and replace the cap. Be sure to dispose of any unused Freon properly. You can usually take it to your local auto parts store for recycling.

Test the Car AC:

The last step is to test the car’s AC to ensure it’s working properly. Start by turning on the AC and setting it to the lowest setting. If the air is cool and coming out at a good rate, you’ve successfully recharged the system. Congratulations! You can now enjoy cool, comfortable air all summer long.

Cost of Recharging Car’s Air Conditioning System

The average cost of recharging air conditioning systems is about $100. However, this cost can vary depending on the make and model of the car.

Some cars may require more Freon than others, so the actual cost may be higher or lower. Additionally, some auto shops charge a flat rate for the service, while others charge by the hour. Be sure to ask your mechanic how they charge so you can budget accordingly.

You can find ac recharging kits at most auto parts stores. The kit will come with the Freon and the necessary hoses and tools to add the Freon to your car’s system.

Here is the breakdown of costs:

AC recharging kit: $60

Freon: $20-30 per can (most cars use 1-2 cans)

Labor: $20-50


If your car’s Freon is low, it can cause several problems. The most common problem is that your car’s air conditioning will not work properly. Low Freon can also cause your vehicle to overheat.

The possible solution is to recharge your car’s air conditioning system.

This article has discussed the symptoms of low Freon, the reasons for it, and how to recharge your car’s air conditioning system.

We hope you can use this information to fix your car’s air conditioning problem. Thank you for reading! If you have any questions, please leave a comment below, and we will do our best to answer them as soon as possible.

Frequently Asked Questions

What happens when your car is low on Freon?

The most likely scenario when your car is low on Freon is that your air conditioning will stop working properly. If your vehicle is low on Freon, the refrigerant will not be able to absorb enough heat to cool the air inside your car properly.

This can lead to several problems, including discomfort for you and your passengers, as well as damage to your car’s air conditioning system.

In some cases, low Freon levels can also cause your car’s engine to overheat. Some other problems that can occur when your vehicle is low on Freon include leaks in the air conditioning system and ice buildup on the evaporator coils.

How often should you check freon levels in your car’s ac system?

There is no definitive answer to this question, as it can vary depending on the make and model of your car, as well as the climate you live in.

However, it is generally recommended that you check your freon levels at least once a year or more often if you notice any problems with your car’s air conditioning system.

Can you recharge the car’s ac system yourself?

In most cases, yes. You can purchase a recharge kit from most auto parts stores, which will come with the Freon and the necessary hoses and tools to add the Freon to your car’s system. But, some vehicles may require special tools or equipment to recharge the system properly.

What are the major types of freon for a car’s air conditioner?

The two most common types of Freon for a car’s air conditioner are R-134A and R-12. R-134A is the most common type of Freon, and it is used in most newer cars. R-12 is an older type of Freon, and it is not as common as R-134A.

Some of the latest cars might use R-1234yf, a new type of Freon. It is not compatible with the older types of Freon, so you will need to use a different recharge kit if your car uses this type of Freon.

How long does refrigerant last?

The lifespan of a refrigerant can vary depending on the type of Freon. For example, R-134A Freon can last up to 15 years, while R-12 Freon only has a lifespan of about 12 years.

However, the lifespan of a refrigerant can also be affected by factors such as how often the air conditioner is used and the climate you live in.

Is it bad to run your car’s ac system on low freon?

It is generally not recommended to run on low freon in the car. This is because doing so can put unnecessary stress on the system and potentially lead to damage or other problems down the line. Whenever you observe signs of low freon in the air conditioning unit, take your car to a mechanic.

Sign up for our Newsletter

Related Articles