The AC compressor is an essential component of your car’s air conditioning system. It plays a significant role in pressurizing and keeping the air refrigerant circulated so that you can have an optimum operating air conditioning system.
The AC compressor works by switching ON and OFF continually, making it prone to wear and tear whenever you turn it on. Just like any mechanical component in your car, it tends to fail over time and needs replacement.
When the car AC starts wearing out or failing, it will show symptoms of a bad ac compressor to tell the driver that it has a problem and needs to be changed.
Since the AC compressor is responsible for pressurizing and circulating the AC refrigerant, a problem with it will negatively affect the entire air conditioning system.
Before you go any further, here’s what you’ll learn; how to tell if a car’s ac clutch is bad, what the AC compressor does, and how to diagnose and replace the car’s AC compressor.
Introduction to A/C Compressors
The A/C compressor is responsible for compressing the refrigerant and circulating it throughout the system. Think of it as the heart of the A/C system. Here’s how it works:
- The compressor takes in low-pressure cool refrigerant gas.
- As the gas enters the compressor, its pressure and temperature increase significantly.
- This now-hot gas moves to the condenser where it loses the heat and transforms into an extremely cold high-pressure liquid that absorbs heat from the cabin.
- This liquid then passes through the expansion valve, turning back into a low-pressure gas, and the cycle starts over.
What does the AC compressor do?
The compressor is a part of the high pressure side of the A/C system, which converts refrigerant gas to liquid as it passes through the condenser.
The compressor does exactly what it sounds like, it compresses the refrigerant gas which then makes it very hot. This is passed onto the condenser which cools the gas, converts it to liquid and circulates it to the receiver drier and expansion valve.
From here it enters the evaporator, where it is exposed to warmth from air in the cabin and turns back to gas.
As the name suggests, it ‘evaporates’ and as a result becomes very cold. This cold is conducted through the metal tubes and fins of the evaporator to deliver cool, dry air into the cabin as dictated by the blower fan.
As you can probably tell by now, the compressor is an essential part of this process.
AC Compressor Location
Your A/C compressor will usually be located somewhere on the auxiliary drive belt. It will have two refrigerant pipes connected to its body, and an electrical plug to provide power.
The AC compressors are usually located towards the bottom of the engine, below your alternator and power steering pump, so you may check from underneath your vehicle to see the compressor.
Why Is It So Important?
The AC compressor makes air conditioning possible in your vehicle. Without it, you will not be able to change the temperature of the air from your vents.
An AC system that functions properly makes driving on a hot day comfortable as well as enjoyable. If for any reason the compressor fails, then the air vents in your vehicle will suck in the hot and humid air from the surroundings and blow it back into your car.
Symptoms of a bad Ac compressor in a car
Identifying symptoms of a bad Ac compressor in a car is not as difficult as it may seem. In fact, bad ac compressor signs are simple and Crystal-clear to identify.
Some symptoms will pop up when you have a lousy ac compressor. Watching out for these signs will help you diagnose and replace your AC compressor and save you from repair costs.
- High cabin temperature
- Loud noise from the AC compressor
- Moisture leak
- Is the compressor clutch stiff or not moving
- Tripping circuit breaker
- Broken Suction Lines
#1. High Cabin Temperature.
One of the first signs to know you have a failed AC compressor is when your dashboard AC vent is no longer sending cold air inside the car.
A failed or bad air conditioning compressor will not circulate refrigerant in the air-con system, and the outcome will be warm air coming through the AC vents. So, when the AC compressor fails, you’ll notice high degrees and hot airflow inside the car.
However, there are three possible reasons behind the hot airflow inside your vehicle; the first could be a refrigerant leak, the second is a low refrigerant, and the third is a failing AC compressor that needs replacement.
#2. Loud noise coming from the AC compressor.
When your vehicle’s ac conditioning system operates, it produces a clicking noise when switching ON and OFF. But if you notice loud noise when the compressor switches ON, it’s a sign your AC clutch is bad.
The ac clutch is a vital part of an ac compressor that drives the belt that connects the AC compressor to the engine pulley. And when it fails, it can either seize or run freely, thereby making a hell of a noise.
Also, the AC compressor is made up of various interior components and utilizes a sealed bearing to spin. If the internal bearing is damaged or seized, or any of the interior components fail, it will produce all sorts of noise.
The ideal solution is to diagnose and see if the clutch is the culprit or if the compressor is damaged and replace it.
#3. Moisture leak.
Most people who ask, can I drive my car with a bad ac compressor don’t know the effects of moisture in-vehicle ac compressor.
The air conditioning refrigerant helps the AC system cool down warm air, and if the AC system runs out of refrigerant, your AC will only produce warm air.
Refrigerant leaks do not only increase harmful health concerns it also causes energy consumption. Refrigerant leaks are significant symptoms of a bad ac condenser in a car.
#4. Compressor clutches stiff or not moving.
The compressor clutch connects the compressor to the engine pulley with a serpentine belt; it also allows the compressor to engage and disengage from the engine power so that the compressor will only spin when it has to.
If the clutch fails, seizes, or is damaged, the compressor will no longer receive engine power.
The good news is, that the AC clutch is a separate unit; after diagnosis, you can decide to replace the clutch or the whole compressor unit. Since the clutch is a separate unit, you can save some cash and replace only it.
#5. Tripping circuit breaker.
If your vehicle’s outside condensing unit keeps tripping the circuit, it indicates a lousy or failing ac compressor. This is because the compressor is overheating and drawing much power resulting in tripping the circuit breaker.
Suppose you notice your circuit breaker is tripping, do not keep resetting it and switching on the system. The circuit breaker is only doing its job and protecting you and your vehicle from a fire outbreak.
#6. Broken Suction Lines.
Your vehicle refrigerant line can block when you have a failed or damaged ac compressor resulting in hot airflow from your air vent. Unblocking refrigerant lines requires an HVAC expert’s assistance, or you might decide to replace the lines if you trust your gut.
What Causes an AC Compressor to Fail?
Several factors can contribute to the failure of an AC compressor. Some of the most common causes include:
- Lack of lubrication: The compressor relies on oil to lubricate its moving parts. If the oil level is low or contaminated, it can cause the compressor to overheat and fail.
- Clogged or blocked components: Dirt and debris can build up in the AC system, causing blockages that affect the compressor’s function.
- Wear and tear: Like any machine, the compressor can wear out over time due to constant use, leading to eventual failure.
- Electrical issues: Faulty wiring or a malfunctioning clutch can prevent the compressor from engaging, leading to poor performance.
- Refrigerant leaks: If the system loses refrigerant, it can put extra strain on the compressor, causing it to fail prematurely.
Consequences Of Ignoring A Bad AC Compressor
Of course, the most noticeable consequence of leaving your car’s compressor unrepaired is that driving conditions are more uncomfortable. It gets more humid inside, plus the heat can be unbearable. But there are other consequences too:
- Other A/C parts can get damaged because the system has leaked out the refrigerant and oil, straining the system and starving it of lubricant.
- The serpentine belt could break while you’re driving, and that could lead to a loss of key systems like power steering.
- It can increase repair costs significantly since additional repairs could be required.
- Your car is worth less than it could be if you decide to sell it.
How to diagnose car AC compressor?
Diagnosing a bad car AC compressor requires a combination of visual inspections, sound tests, and pressure tests. Here are some steps you can follow to diagnose a bad compressor:
Visual Inspection
Start by visually inspecting the compressor and surrounding components for signs of damage or wear.
- Leaks: Check for signs of refrigerant leaks around the compressor, condenser, and other components.
- Corrosion: Check for signs of corrosion or rust on the compressor and surrounding components.
- Wear and tear: Check for signs of wear and tear on the compressor’s moving parts, such as the piston and cylinder.
Sound Test
Next, perform a sound test to check for unusual noises coming from the compressor. Listen for:
- Clunking or grinding sounds: These sounds may indicate a problem with the compressor’s moving parts.
- Hissing sounds: These sounds may indicate a leak in the system.
Pressure Test
Finally, perform a pressure test to check the system’s pressure levels. This can help identify:
- Leaks: A pressure test can help identify leaks in the system.
- Refrigerant levels: A pressure test can help identify low refrigerant levels.
How do you change an ac compressor?
As the name indicates, the AC compressor compresses the refrigerant into a high car AC pressure and circulates the gas within the air conditioning system.
Without the AC compressor, the refrigerant won’t circulate in the AC system, and you will notice your air vent not blowing cold air. Without further ado, let’s get started with how to change the car’s ac compressor.
Things and materials needed:
- Thread lock
- Screwdriver drivers
- Pliers
- Ratchet handle
- Universal joint socket
- Wrenches
- Socket sets
- Clean rag
- Compressor oil
- Refrigerant
- Cup bolts
Step 1. Removing the compressor unit from the engine bay
First, take off your battery negatively terminal so you won’t have a jolt of electricity or get a short circuit. Remove any covering on your engine so you can access the serpentine belt.
Take the right tool from your mechanic tools box and pry the belt tensioner, and the belt will slip right off. Locate all the tubes and hoses on the compressor and disconnect them.
Depending on your vehicle model, there may be other components or accessories blocking easy access to the compressor. Grab the proper wrenches and remove these components by loosening and disconnecting the bolts and wirings.
Ensure you have a cup bolt where you put all the bolts and connectors you removed from the engine. Locate the high and low-pressure lines on the compressor and unbolt the fittings.
Take a piece of clean rag and block off the ends of the refrigerant lines so that dirt and grits will not enter the hole. Locate the electrical connector on the compressor unit and pry it off with your flat head screwdriver.
Now, it’s time to get right on the lower and upper mounting bolts using the correct sockets and ratchet handle.
You might also need a universal joint socket to loosen the mounting bolts. First, break free all the bolts before loosening them.
You need to hold the AC compressor unit by hand while taking off the last bolt, so you won’t wind up causing hazards to yourself or the compressor.
Step 2. Inspecting the old compressor
It is necessary to inspect the old compressor unit before disposing of it. By so doing, you will find out why it failed. If you hear a grinding noise when spinning the compressor clutch, that’s an indication there are metal shavings that need to be flushed right off.
Get an air conditioning flush kit from any reliable or local store and unblock the orifice tube or expansion valve. Inspect the exhaust ports and refrigerant lines for metal shavings and clean them. You might have to change the orifice tube if it seems wholly blocked.
Step 3. Accessing the new ac compressor
Bring the new and the old compressor units close and access them. They may vary slightly in design as there are many AC compressor manufacturers, but the installation process should be the same.
The exhaust and the intake port must be the same. Check the AC clutch outside diameter and the number of ribs on it. Check if there are accessories on the old compressor that are not on the new unit and transplant them.
Check the new compressor user guide and see if it has pre-added oil; if not, add the recommended amount of oil. Take your wire brush, clean the old bolts, add some thread lock if you want to, and mount the bolts on the new compressor.
Step 4. Replacing the O rings
The compressors’ high and low-pressure refrigerant lines utilize o rings to ensure there are no refrigerant leaks. When replacing your vehicle’s ac compressor, you need to replace those seals to prevent refrigerant leaks.
Head over to both high and low refrigerant lines, carefully remove the old seals, replace them with ones, and rub the oil.
The new o rings should match the refrigerant lines like the old ones. Do you want to proceed without replacing the old o ring? That’s not a good idea; it can cause refrigerant leaks.
Step 5. Mounting the new compressor
Take the new compressor to the engine bay and place it on the compressor sitting where you removed it. Fix the compressor and snug bolts by hand and later torque the bolts with sockets or wrenches.
Take off the blockage on the high and low refrigerant lines and install them; ensure both lines are well-tightened.
Install all the accessories you removed earlier, such as the electrical connector, serpentine belt, and any component you removed, to access the compressor unit.
Then, take the final step by filling the refrigerant into the AC system. Watch this YouTube video for a visual clarification on Car ac compressor replacement.
Can You Drive with a Bad AC Compressor?
It is generally not advisable to drive with a bad AC compressor. While the car may still be drivable, a faulty compressor can lead to further damage to the air conditioning system.
Additionally, driving without a functioning AC can be uncomfortable, especially during the hot summer months.
If the compressor is not working properly, it may also strain the engine and reduce fuel efficiency, leading to higher operating costs.
What Is The AC Compressor Replacement Cost
The truth is, replacing a vehicle’s AC compressor isn’t cheap. On average, expect to pay $1,000 to $2,000 for professional replacement. Here’s how it breaks down:
- Parts Cost: A new, good quality AC compressor typically costs between $400 to $1,000 depending on your vehicle’s make and model. High-end or luxury vehicles may have even higher part costs. While you may be able to find 3rd party compressors compatible with your vehicle for $150 to $200, the quality can be hit or miss and many mechanics won’t install them for you or warranty the job.
- Labor Cost: Because the complete replacement procedure usually takes anywhere from 4 to 8 billable hours, a large chunk of your final bill will be labor. Expect anywhere from $300 to $1,000 on labor costs, with the hourly rate mainly determined by type of shop and location.
- Additional Expenses: It is often recommended to replace the AC condenser and expansion valve at the same time. In fact, some manufacturers require it for the warranty to be in effect. Because of that, your final total might be $100 to $400 higher.
Before committing to a full replacement, have your entire AC system inspected. Sometimes, issues that seem like compressor failure can be caused by simpler, less expensive problems like a worn belt or low refrigerant levels.
As with any expensive service, get multiple quotes from reputable shops. Sure, it may be a small hassle, but the few extra minutes spent can often save you hundreds of dollars.
If you’re comfortable with auto repairs, you can save a good amount of money by replacing the compressor yourself.
However, it’s no simple task and proper handling of refrigerant requires special equipment and knowledge. With AC compressor replacement, a large majority of car owners prefer to leave this job to the pros.
FAQs.
Q: How long should a car ac compressor last?
As long as you have a desirable driving experience and your vehicle is running optimally, you might not bother to know the components and accessories working in the engine compartment.
As many air conditioning components make up the AC system, it is hard to say how long the AC compressor can last accurately. The answer depends on age and how often you use your car ac.
As you drive your car for a long time, the AC compressor will start malfunctioning. However, you can expect your AC compressor to last 8-12 years.
Q: How much does it cost to replace an air conditioner in a car?
The cost of replacing or fixing an air conditioner in a car varies significantly from vehicle to vehicle. Minor ac repair like refilling refrigerant and replacing sensors and hoses can cost $200 to $700.
On the flip side, major ac repair like replacing ac condenser, compressor, or evaporator can cost $400 to $3500. The variation in replacement cost depends on your vehicle, location, and the garage you go for the replacement.
A mechanic can charge $150 for replacing ac compressor, and another mechanic will charge $400 for doing the same job.
Q: Can I replace the car ac compressor myself?
Car ac replacement should be done by an HVAC expert. However, suppose you’re a competent DIY and confident enough.
In that case, you can follow the guide in this article to successfully replace the AC compressor and save a decent amount of repair cost.
Q: Do you need to replace the dryer when replacing the car ac?
It is essential to replace the dryer when changing the car ac compressor unit. In fact, most warranties recommend you to change the AC dryer whenever you work on the AC conditioning system.
Final word
If you notice the symptoms of a bad ac compressor, the next thing you want to do is carry out a car ac compressor diagnosis to be sure the AC compressor is the culprit. Replacing a vehicle ac compressor yourself can be an expensive, time-consuming fix.
The ball is in your court to decide whether or not you want to replace the AC compressor yourself. The fact is, the summertime can get incredibly hot. Sweating and driving during a hot afternoon might not be something you want to experience.