A vehicle’s air conditioning AC system comprises of distinct elements. The AC compressor is just one of the essential parts that make up the whole of this system. Without it, the entire AC system cannot perform its duty of creating cool air inside the vehicle and you will have to deal with AC compressor replacement cost to bring it back to life when it breaks down.
The primary function of the AC compressor is to put the required amount of pressure (to compress) on the car’s refrigerant to activate its heat transfer characteristics and change the temperature.
This enables the driver and the passengers in the cabin to remain cool during the warmer seasons and also to have a clear shield against the wind in the colder seasons. But just like any other vehicle, components can experience wear and tear and become inefficient over time, the AC compressor isn’t an exception.
In this article, we delve deeper into the major function the AC compressor plays in your vehicle’s air conditioning; the symptoms associated with a malfunctioning AC conditioner; the AC compressor replacement cost, and good maintenance practice to ensure it lasts longer.
In this article:
What’s An AC Compressor?
As stated earlier, the AC compressor is an essential part of a car’s conditioning ability. It is the backbone of the AC system. It’s a pump that creates heat by putting air conditioning refrigerant under extremely high pressure. It’s a “pump” because it can increase pressure in a fluid and can also transport the fluid through a pipe.
Since gases are compressible, the AC compressor helps reduce the volume of the gas. Liquids have got varying characteristics. There are compressible and non-compressible liquids. The AC Compressor pressurizes and transports liquid, too.
The AC compressor comprises two ports, namely inlet and outlet ports. These ports can also be referred to as suction and discharge ports, respectively. The inlet or suction port comprises larger diameter holes. The refrigerant is sucked into the compressor, then compressed and discharged through the outlet headed for condensing. An AC compressor comprises a series of complex passageways, valves, bearings, and other different components.
How AC Compressors Work
Foremost, the AC Compressor works with two guiding principles: evaporating liquids that absorb heat while condensing vapor that transmits heat to surrounding objects. The concept is that simple. It is important to know the relationship between the AC compressor and refrigerant.
Freon is the most commonly used refrigerant fluid that has got the ability to make cold air out of hot air. The refrigerant and the compressor are essential pairs that work in unison to help each other achieve their functions. The AC compressor is propelled by a car’s engine in its key role of compressing the refrigerant used to absorb the heated air inside the cabin of the vehicle.
The most commonly used type of AC compressor is the swash plate. A swash plate AC compressor comprises a pulley and V-belt that drives the compressor, which is often linked attached to a car’s engine block. When the AC system is switched on, the belt drive is set in motion by an electromagnetic clutch.
The Importance Of The AC Compressor
The swash plate moves six double-ended pistons which handle the intake and the compression. It is important nothing that the reed valves control the amount of refrigerant flow. As this takes place, effective lubrication to the moving parts is facilitated by a thin mist of oil that circulates and mixes with the refrigerant.
The AC compressor takes in gas from the refrigerant through the evaporator. This causes the pressure to drop. The lower pressure makes the refrigerant evaporate at a low temperature before the AC compressor takes that cold vapor and compresses it. The refrigerant gas is warmed during this compression and then pushed into the condenser through pipes.
It then turns to liquid form and emits heat before moving into an area to cool. The refrigerant eventually absorbs heat in the cabin compartment. It is then returned to the gaseous state in the evaporator before being sucked in by the AC compressor. This cycle continues as long as the air conditioner is turned on and the output becomes hot air instead of cold.
Importance Of The AC Compressor
How important is it to have an AC compressor in your car? Well, that all will depend on your preference. Do you prefer having that cool air blowing in your car? If yes, then the AC compressor is much more important. This is the heart of your air conditioning system. Your overall air conditioning system needs its “heart” to function efficiently.
An AC system comprises multiple components that work in unison to make cool air blow through a car’s vents. Refrigerant is another very important component of the AC system. It makes cool air by circulating throughout the coils and valves of the AC system. The refrigerant also works along with some other parts, like the drier, the expansion valve, and sensors to help bring that cool temperature to the car.
This refrigerant and all the other components that make the system are worthless without the AC compressor. This magical little pump moves the refrigerant throughout a car’s AC system. The compressor keeps the flow of refrigerant going and keeps your vehicle cool. By helping to circulate and compress the refrigerant throughout your AC system, the AC compressor helps keep everything running smoothly.
AC Compressor Doesn’t Work: Is AC Compressor Replacement Cost Next?
If you’re okay doing without air conditioning, then this part may not be so important to you. However, if you are fairly uncomfortable with being uncomfortable with the high temperatures in your car, then you want to get your AC compressor checked and fixed ASAP by an AC compressor specialist if it cannot function well.
Types Of AC Compressors
The three common types of AC compressors used in vehicles include:
1. Rotary Compressors
Rotary compressors compress and transfer refrigerant gas using a roller or cylinder mechanism, according to Four Seasons Controlled Climates. The roller rotates inside a cylindrical compartment that’s divided in two by a spring-mounted blade. This is how the refrigerant is compressed. In effect, the blade creates two sealed-off areas within the cylinder.
As the roller rotates inside the cylinder, variable pressures build up on both sides of the blade. As pressure build-ups on one side, and then compressed, cooled gas is forced out on the other.
2. Scroll Compressors
Scroll compressors comprise two spiral disks of different heights, with the shorter disk sitting inside the taller one. The tall disk remains stationary while the short disk compresses the refrigerant gas by rotating inside the tall disk.
As the short disk rotates, it creates sealed-off areas inside the tall disk, which contain varying degrees of pressure. As the refrigerant is suctioned into the scroll, some of it gets trapped inside the sealed-off areas.
The rotation of the short disk causes the gases to move towards the center of the scroll, which is how the gases are compressed. Cooled air is compressed, and then exits the scroll through an outlet along the tall disk wall.
3. Variable Displacement Compressors (Fixed Swash Plate)
These compressors are also known as reciprocating compressors, as they compress and transfer refrigerant gas using a piston or cylinder mechanism. The upward or downward motion of the piston creates varying degrees of pressure that work to suction refrigerant gas into the cylinder, compress it and expel the resulting cool air out into the car’s interior.
These pressure variations also work to open and close the intake valve, as well as open and close the exhaust valve. They are the most commonly used in modern vehicles.
Other Types Of Compressors
- Maximized performance and high efficiency because of its lightweight design.
- Quiet and reliable because of its smooth pumping operation.
- Durable, lightweight, and compact piston design.
Compact Variable Compressors (CVC)
- Founded on the swash plate design used on Delphi V5 and V7 compressors.
- Improved air conditioning performance and fuel economy because of its smooth operation without clutch cycling.
- Meets vehicle air conditioning demand with adjustable displacement capability.
V5 and V7 Compressors
- Improved air conditioning performance and fuel economy because of its smooth operation without clutch cycling.
- Meets vehicle air conditioning demand with its adjustable displacement capability.
- V7 compressors feature increased capacity, reduced noise, and minimized vibration.
- V7 compressors are compatible with R-134a systems.
- V5 compressors are compatible with R-12 and R-134a systems.
- Extremely efficient and lightweight.
- Improved OE design for increased performance and reliability.
Components Of An AC Compressor
- Housing that contains the compressor’s section, oil fill, and valves.
- Connecting points used for refrigerant pipe connections.
- Pulley with electromagnetic (EM) clutch.
Symptoms Of A Bad AC Compressor
Symptoms of a malfunctioning AC compressor are clear and very easy to see. Knowing these symptoms gives you the basic knowledge to help you diagnose your car. These include:
1. Higher Temperatures Than Normal In The Cabin
One of the most common symptoms of a bad AC compressor that can be easily identifiable is an AC failing to blow as cold as it used to do. A damaged or failing compressor will not be able to properly regulate the refrigerant flow in the AC system, and as a result, the AC will not function efficiently. So you may notice that the temperature inside the car increases and the airflow from the AC is hot. There are 3 reasons behind this:
- The low level of the refrigerant.
- A leak of the refrigerant.
- The compressor is faulty and needs to be replaced.
2. Loud Noise When Compressor Is Running
When the heating, ventilation, and air conditioning system operation, it produces some noise when it’s going on and off. But the loud noise when the AC switches on is another potential symptom of a bad AC compressor. The AC compressor has several interior components and uses a sealed bearing to turn.
If any of the interior components break, or the compressor’s internal bearings fail, then unfamiliar noises can be produced. The most valuable solution is to change the whole AC compressor.
3. Moisture Leaks
The refrigerant helps the AC unit turn warm air into cold air, and if it runs out of this chemical, your AC will blow warm air. When the refrigerant leaks out, it not only increases the potentially harmful health concerns but also increases the car’s energy consumption.
4. Compressor Clutch Is Not Moving
The clutch on the compressor allows the pulley to engage and disengage from engine power so that the compressor is only turning when it is supped to. The clutch keeps the compressor activated. If it breaks, the compressor cannot receive the engine power anymore.
The repair expert will check the serious level of the compressor clutch, then they may decide to replace the clutch only or the whole compressor. Since it is possible to replace the clutch, it will reduce the AC compressor replacement costs.
5. Circuit Breaker Tripping
When a car’s outside condensing unit keeps on losing power and tripping the circuit, it is one symptom of a malfunctioning AC compressor. This is usually caused by overheating and drawing too much power, causing the circuit breaker to trip. When this happens, do not just keep resetting the circuit breaker and turn the system back on. The circuit breaker fuse is doing a precautionary job to protect you from a potential fire hazard.
6. Broken Suction Lines
The refrigerant line in the AC system can be blocked if the compressor cannot operate, leading to the result of hot airflow in the car. You can fix this problem by taking your car to the service mechanic. The automobile service expert will try unblocking the refrigerant passageways, but if this approach fails, the entire passageway will need to be replaced.
7. Damaged Wire
If you normally do the maintenance of your car at home, you may notice damaged wiring of any kind. This is a bad AC compressor symptom. Damaged wiring presents a huge safety concern because it can easily lead to an electrical fire.
When an AC system is exposed to electrical problems, it can lead to the compressor receiving too much or too little voltage. This quickly damages the compressor and results in the replacement of a new AC compressor.
Causes Of AC Compressor Failure
These are the common issues that can cause AC compressor failure in your car:
1. Dirty Coils
If dust, grime, and mineral scales build up on the condenser coil, the air conditioner can’t expel enough heat from the system and it is forced to run constantly trying to cool your space. The increased pressure and temperature can cause the compressor to overheat and fail.
2. Blocked Suction Lines
When your air conditioner’s refrigerant lines become blocked or damaged, the first thing you’ll notice is that the unit is not cooling as effectively. If the problem is not fixed, once again, the increased pressure and temperature cause overheating and AC compressor failure.
3. Low Refrigerant Charge
If your system’s refrigerant lines develop holes or cracks, the air conditioner leaks refrigerant. After a while, the level becomes so low that the compressor has to work harder to pump enough refrigerant through the system to cool your space. The strain can eventually cause the compressor to break down.
4. Incorrect Suction Line Size
If your refrigerant line develops leaks and needs to be replaced, make sure you get an experienced AC technician to do the job. A line that is too large or too small for your system can cause premature AC compressor failure.
5. Too Much Refrigerant
If a less experienced person works on the air conditioner and accidentally adds too much refrigerant or even the wrong type of refrigerant, it can be a deadly mistake for the compressor.
6. Electrical Problems
An electrical failure can cause a build-up of acids that cause a great deal of damage to other parts, besides the compressor. If you have a failed compressor, make sure the technician tests for these acids. If such acids are found, then it means an electrical burnout has caused damage to the entire system and is probably beyond fixing.
Electrical problems are often easily preventable when an experienced technician inspects the system: he can spot and repair damaged wiring, fuses, and contractors before they take down the entire system and cause AC compressor failure.
7. Contaminants In The System
High heat and pressure in an air conditioning system can introduce several contaminants that can cause damage. These include air, moisture, dirt, debris, leaves, soot, acids, and even bird and pest droppings.
8. Inadequate Oil Lubricant
If there’s not enough lubricant, the system can’t work properly and all kinds of problems can result, including AC compressor failure. When your system is regularly maintained by a trained AC professional, he will check the lubricant levels and the condition of the oil pump to prevent this problem.
AC Compressor Replacement Cost: Troubleshooting
Vehicle air conditioning is something that many car owners ignore until the unit stops working completely. It can be unpleasant reaching down to crank up your AC compressor on a hot day and all that comes out is hot air. A bad compressor can be a deadly hazard.
If the compressor’s bearing cannot function, your engine can seize because of a stuck compressor. If you are traveling at speed and the car shuts off, you no longer have power steering, nor is your brake booster functioning.
There are a few reasons your AC system might stop working and the central part of it is the AC Compressor. Below are a few tricks on troubleshooting your AC compressor.
If the air temperature does not cool when the AC system has engaged, there was an AC compressor failure. If the AC still works, check to see if the temperature fluctuates while the AC system is running.
Find your AC compressor and visually inspect it for rust, physical damage, oil leaks, or paint damage. These are signs of a car’s AC compressor failure. With a lack of oil, the compressor will not function efficiently and will cause premature wear. The increased friction will also lead to erratic temperatures when the AC system is engaged.
Check your belts to ensure there is proper tension and the belts are not damaged. Cracked or splitting belts can cause further damage to your AC compressor. If they are bad, they should be replaced with a new compressor.
Inspect the clutch at the front of the AC compressor and make sure the clutch rotates freely. As you turn the clutch hub, there should be minimal resistance. A bad clutch will lead to a bad compressor and vice versa. We recommend if one goes bad, both should be replaced.
With the engine running, turn the AC to its coolest setting and the fans to the highest setting. Open up the hood and listen for the AC compressor and clutch to engage. A car AC compressor failure will not engage and will often lead to skipping and squealing caused by the friction of the belt.
Find any refrigerant leaks. The AC system is closed and should not leak, nor should the refrigerant level be low. Low refrigerant means you have a leak in the system. The best way to test your system for leaks is with an electronic AC refrigerant leak detector that can detect small traces of refrigerant. There are other tests that use a special dye that shows up under UV light.
If you have completed these steps and believe your car’s AC compressor is failing, it is best to replace it. We recommend that when changing your AC compressor and clutch, you also replace the accumulator, expansion device, and O rings. By replacing these, you will not have to do the job more than once.
AC Compressor Replacement Cost
The AC compressor is a very significant component of any vehicle. It will not be cheap to replace it after it goes bad. Usually, the average cost of replacing a new AC compressor is somewhere between $800 to $1,200 for the complete replacement of the compressor. This amount also includes the cost of purchasing the new component itself that will cost anywhere from $650 to $1,000 or more. The labor costs will be anywhere from $150 to $200.
AC Compressor Replacement Cost: Maintenance
Thankfully, maintenance of your AC compressor is rather minimal and includes:
- Regularly use the compressor to keep all the elements of the system properly lubricated.
- Charge your refrigerant to ensure the proper levels of pressure in the air conditioning system.
- Clean and tighten the drive belts as necessary.
- Perform electrical checks on the switches and sensors, as well as the EM clutch’s fuse, relay, and coil.
The most common reasons that an AC compressor will fail are wear and tear due to age or neglect. If you experience a compressor failure, you will need to replace it. It is important to remember that if you use one that has been re-manufactured; you need a recovery machine to protect your atmosphere while extracting the refrigerant. Note that while you can replace certain EM clutches, some are replaced only as an assembly, as with all motor-driven compressors.
AC Compressor Replacement Cost: Final Thoughts
Different issues can cause your air conditioner to fail. Fortunately, they are not all expensive fixes. The problem could be just a minor loose wire that causes a power failure in the car’s air conditioner. Or, it may be just a clogged air filter that is impeding air from flowing into the system.
When AC compressor failure causes a complete breakdown of the entire system, you may have to deal with a major AC compressor replacement cost that will require you to dig deep into your pocket to have it fixed. The compressor is an essential and expensive component. When it breaks down, you may use lots of cash on a new AC unit.