Signs of Too Much Freon in Car AC and Fix

Freon plays a crucial role in the cooling operation of every car’s air conditioning system. However, too much freon in car AC can be disastrous for the system.

If your air conditioner blows warm/hot air, builds up the ice around the vents, produces a hissing noise, or releases an offensive chemical smell, you most likely have too much freon in the system. Although this may seem like something you can manage for a while, it is an imminent disaster.

So, carefully study this article to learn more about the symptoms of excess freon in a car’s air conditioning system, the causes of overcharged AC, and how to discharge the excess refrigerant in the AC.

too much freon in car ac

The Role of Freon in Car AC Systems

Freon is a refrigerant used in most car AC systems. It cycles through the system, changing from a low-pressure gas to a high-pressure liquid and back, absorbing and releasing heat in the process. This is what cools the air blown into your vehicle.

This guide to car AC emphasizes the critical role of Freon in the functioning of car air conditioning systems. Freon gas, crucial for cooling operations, can lead to disaster if the system charge exceeds recommended levels. Too much Freon disrupts the balance, leading to warm discharge air—a symptom of system malfunction. Car AC symptoms may include inadequate cooling effects within the cabin, signaling a disruption in the principal operation.

The usage of air tools like gauges and nozzles for reading pressures can diagnose excess Freon. It’s vital not to face complacency; ensuring proper charge levels maintains system efficiency and prevents cooling results from being compromised.

Symptoms of too much freon in Car AC

An overcharged car AC system produces apparent signs that let you know there’s a problem with the component.

Besides the symptoms outlined above, other signs could reveal that you have too much freon in your car AC. However, let’s see some of the common symptoms below.

No cooling/warm air circulation

One of the foremost signs of too much freon in a car’s air conditioning system is a lack of cooling when the AC is working. Instead, the AC may release warm or hot air from the vents. This is because the refrigerant does not have enough space to depressurize due to the excess content.

In some cases, you may experience minimal cooling from the AC, similar to the air outside the car’s atmosphere. If you’re experiencing any of these signs, it is traceable to excessive freon in the air conditioner.

Lack of air circulation

While most car AC systems may not cool appropriately or release warm air due to excess freon, some cars are designed with an air conditioning system that will not circulate air under the same condition.

This is a safety measure to prevent the AC from any damage resulting from excessive Freon. So, if your AC suddenly fails to work after recharging, could it be that the system is overcharged?

Noisy compressor

The compressor is built to transport the refrigerant via the lines into the air conditioning system for operation. It is designed to release a specific maximum refrigerant per time. Therefore, an overcharged AC system will make it difficult to decompress the liquid into a gaseous form.

The compressor will have no choice but to release the liquid coolant instead of the gaseous form of the coolant, which requires much pressure. So, the pressure causes the compressor to become less effective and noisy as the operation continues.

Poor acceleration

The air conditioning system is built to work in synergy with a car’s engine. The compressor relies on the engine’s effort via a belt to trigger the AC operations. In other words, too much freon will mount more pressure on the engine and result in poor acceleration.

Although there are several causes of poor acceleration in a car, you may want to check out the freon level if you have exhausted other reasons.

Engine overheating

Undoubtedly, there are various causes of engine overheating. However, a leaking coolant or excess refrigerant can also be a culprit. If you suddenly experience overheating after recharging your AC, it’s most likely overcharged.

Therefore, check it out properly if you can’t find any other reason for the overheating. Meanwhile, engine overheating can be disastrous if you ignore it.

Causes of overcharged AC

Incorrect DIY refill

Performing most vehicle repairs and component or fluid replacement/change requires a well-defined procedure. Only DIYers who understand the nitty-gritty can do the task without messing things up.

So, performing a car AC recharge without proper knowledge of the required procedure can fill in too much Freon into the air conditioning system.

Bad pressure gauge

Some AC recharge kits designed for DIYers come with a unique gauge that guides the process of refilling the refrigerant. The gauge is supposed to notify the user of the extent to which the freon should go in the air conditioner.

In other words, a bad pressure gauge will not be able to reveal the level of the refrigerant, thereby misleading the DIYer. In addition, this can lead to excessively recharging the AC.

Fear of running out of refrigerant

Another reason a car’s AC may be overcharged is due to the fear of running out of refrigerant. This is common with newbies who are skeptical about running out of coolant, thereby refilling the AC over again when it is yet to require a recharge.

How To Discharge Car AC

The solution to excess freon in a car’s air conditioning system is to discharge the AC. The process is pretty straightforward. So, let’s jump on it immediately.

Locate the AC low-pressure port

First and foremost, locate your car’s air conditioner’s low-pressure port to commence the discharge process. The AC low-pressure port is located near the AC compressor on the lines.

However, your car manufacturer’s manual should accurately describe the low-pressure port’s unique location.

Connect your refrigerant can to the AC low-pressure port

After locating the low-pressure port, the next thing is to connect the refrigerant can to that port. Meanwhile, ensure that the refrigerant can is correctly connected without any space that can accommodate leaks.

Start the car’s engine

Start the car’s engine to enable the freon to move through the air conditioning system for easy discharge.

Open your refrigerant can

Once the car’s engine starts running, carefully open the refrigerant can. Then, add some freon to discharge the existing refrigerant from the system. Be careful not to add too much refrigerant.

Close the refrigerant can and disconnect the low-pressure port

After adding up the necessary quantity of refrigerant, close the can and carefully disconnect it from your low-pressure port without any leaks in the system.

Turn on the air conditioner

Now, turn on your car’s AC while the engine is running so that the new refrigerant can move through the entire air conditioning system for appropriate distribution. This should rectify the issues with the formerly overcharged AC.


What happens if I put too much freon in my car AC?

Although freon is necessary for your car AC to work, putting too much freon in the air conditioning system will hinder the component’s effectiveness.

In addition, too much freon can also damage the air conditioner’s compressor. So, it would be best to follow the manufacturer’s instructions when refilling your car’s AC with freon.

excess freon

How much does it cost to evacuate car AC?

Evacuating a car’s AC system costs around $118 to $280, depending on the car’s make and model. Sometimes, the problem necessitating the evacuation may also impact the total cost.

Meanwhile, if you just changed your AC compressor or fixed a component in the system, these may cause the AC to require an evacuation. However, air and moisture removal are the major reasons you must evacuate the AC.

Can you release Freon into the air?

The answer is a capital NO! It is entirely illegal to vent or release Freon into the atmosphere deliberately. Furthermore, there are severe penalties for not complying with this prohibition as the Environmental Protection Authority (EPA) has been mandated to punish offenders.

Therefore, finding out how to discharge excess freon from a car’s AC is vital to avoid the consequences of doing it the wrong way. Otherwise, contact your auto mechanic to do the job.

Can you mix Freon and 134a?

Mixing freon and 134a is not ideal as the resultant effect is not good. Since the chemical compounds of the two gases are different, the mixture will cause a black death.

The black death is the spreading of black coating within the air conditioning system’s interior due to a chemical reaction induced by AC heat.

Can you mix old and new Freon?

Again, the answer is a capital NO! You should never attempt mixing old and new freon in your car’s air conditioning system. The gases may trigger an adverse reaction due to pressure and temperature, resulting in costly damage to the air conditioner.

Therefore, no matter what, stick to the recommended refrigerant for your car’s AC and follow the manufacturer’s instructions to get the best out of the product.


Too much freon in car AC may not lead to instant damage to the air conditioning system. However, it will usually reveal minor to complex signs like inability to blow cold air, warm air release, noisy compressor, poor acceleration, overheating, etc.

Once you start experiencing any of the symptoms above, check out the freon level as it may be too much. If that’s the case, follow the procedure above to discharge the AC or contact an expert auto technician to perform the task.

Solomon Osuagwu

Osuagwu Solomon is a vetted auto mechanic with over ten years of experience in the garage and five years of experience as a service writer. He prides himself in writing accurate information on professional repair guides, DIY repair guides, buyer’s guides, comparisons, and car reviews. If he’s not in his repair garage, he’s writing automotive blogs to help car owners and fellow mechanics to troubleshoot and proffer solutions to several car problems.

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