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What Happens If You Put Too Much Freon In A Car?

What Happens If You Put Too Much Freon In A Car?

Your car’s air conditioning system immediately comes to your rescue if it’s scorching outside. However, what if your car’s AC unit is not circulating cool air as it’s supposed to do? What are the possible reasons for the malfunctioning of the air conditioning unit?

Well, if you’re not a mechanical engineer or don’t have much knowledge about the same, you may not be able to conclude anything.

However, there is one thing even a novice like you can consider as the probable cause in this case. That’s overcharging your car’s air conditioner with the freon gas. It’s a compressed gas that’s responsible for the cool air every AC unit throws out.

But its overcharging can produce negative results like the above one. Besides, below are other important things you’d know about this magical gas and how it affects your car.

What happens if you put too much freon in a car?

As referenced above, freon is a compressed gas responsible for the correct functioning of an air conditioner. The cool air determines this the unit circulates throughout the car cabin. However, if you have ever tried to top up freon in your car, you might have overfilled it.

It is because you may not know how much is sufficient for the AC unit as it’s supposed to expand inside the chamber. It makes it occupy extra space, and this causes the entire air conditioning unit to behave abnormally.

As a common side effect, excess freon gas can prevent the compressor from working at its capacity. In some cases, extra freon accumulates inside the compressor and results in subcooling or undercooling. In the worst of cases, the freon gas may even damage the internal mechanism of the compressor.

What are the symptoms of an overcharged AC system?

If you don’t know whether you have overcharged your car’s AC system or not, look out for the following symptoms.

Is the air conditioning unit able to throw cold air immediately?

If you regularly drive your car, depending upon the condition of the AC unit, it should start throwing cold air as you press the AC button. In case it’s been a while you took your car to the road, this may take a minute or two. These two are the two most common observations you can bank to determine whether the freon is in the right amount of excess.

If you’re still not sure, the following symptoms are your last resort.

Poor or no cooling

The AC’s functioning relies on the cooling effect of freon. It makes it extremely necessary to have the exact amount of freon in the AC unit. Otherwise, it’ll malfunction. And if there is poor or no cooling, there is excess freon in the car.

However, if your car’s air conditioning unit is still in good shape, you may get slightly cool air at the highest fan speed and lowest temperature. In the worst of cases, overcharging may make your air conditioner function as a heater!

Is the pressure gauge displaying high pressure?

If yes, it’s another proof of overcharging the air conditioning system with freon. Every AC unit has a pressure gauge attached to it to monitor the pressure of freon (and other gases) to regulate their flow. If the reading is high, there are high chances of excess freon in the system.

What worsens the situation is the fact that high pressure is proportional to high temperatures. That is, due to high pressure, the temperature inside the unit will also increase. This high temperature & pressure work in tandem to disrupt the working of the entire unit.

Is there any unusual noise coming from the compressor?

Inside the compressor, freon changes its phase from gas to liquid and vice-versa. For this to happen smoothly, there must be enough space as this also helps the compressor transport the coolant through its lines without effort. However, if freon has occupied all the space, the compressor will have to work harder to get the coolant through its lines. It results in a noticeable noise you can hear.

The AC unit is drawing more power than usual.

It is another common observation of an overcharged air conditioning system. As said above, overcharging makes it harder for the compressor to take the coolant through its lines. Due to this, the compressor ends up drawing more power than normal.

Hence, the drive belt will start making noises or even breaking if the compressor draws excess power from the engine.

A complete breakdown of the compressor

Although modern-day compressors can handle the flow of excess coolant through their lines, they are bound to break down at any moment. If it’s so, the car’s air conditioner won’t start at all until you repair it.

So, these are the major symptoms of an overcharged AC system.

What happens when you overcharge an AC?

When you overcharge an AC with the refrigerant, it can result in a series of side effects depending upon how quickly you act. For example, the excess refrigerant will alter the pressure readings and, subsequently, the temperature in the initial stages.

If not acted upon by now, the excess coolant will accumulate inside the compressor unit and harm its internal components. As a result, the entire compressor unit will break down, leaving behind a non-working air conditioner.

How much freon can a car hold?

Although the exact quantity of freon a car can hold varies from model to model, an average of 3 pounds of compressed freon is what standard vehicles can hold. Since today’s cars have a much more advanced engine and air conditioning system, it’s better to ensure the right amount of freon in your car by referring to the rule book or any mechanic.

Ways to know if your car AC is low on freon

Following are some key symptoms of your car AC running low on freon.

  • Your fully functional air conditioning system blows out either hot air or air at room temperature instead of cool air. Either there is no freon or insufficient freon.
  • In the liquid state, freon appears as grease. Thus, look for anything similar around the compressor lines or inside the car cabin. If there is any greasy substance, it’s probably freon, which means that it’s leaking.
  • On turning on the AC, the clutch engages as it helps the compressor pressurize the freon. If the freon is in a low amount, the clutch won’t engage.
  • Can you see ice on or around the compressor? If yes, it’s another indication of the car running low on freon and moisture replacing freon in the system.

These are the common indications of your car running low on freon.

How often should you change the freon?

There is nothing like an ideal time to change freon. Being a gas, it doesn’t have any shelf life. Still, car experts recommend checking and changing freon every 12-15 years, although it’s still not necessary as long as everything is running fine.

It also means that if freon somehow escapes from the unit due to leaks, you’d have to refill it no matter if all this happens before the stipulated 12-15 years or not.


While the working of an air conditioner is pretty the same you would have studied years back; many people often ignore the freon in the process. It’s the most important component of your car’s air conditioning unit that blows out cool air from the air vents.

If it’s present in high or low quantities, the air conditioning unit will perform badly or even break down completely in the worst of scenarios. Thus, its proper quantity is a must.