An AC system failure might be inconvenient if you plan a long journey. Fortunately, it rarely fails without exhibiting some indications weeks or months beforehand.
Since the AC system is sealed and always under pressure, the hissing sound does not necessarily indicate a problem. Hissing may also be produced by certain engine parts that are deteriorating. Because of it, diagnosing it may be challenging, so be sure to finish reading this article. Here is a concise summary of all the potential causes, however.
Remember that it is typical for certain automobile AC systems to continuously hiss if you hear a hissing noise from the air conditioner. However, if you have just lately been aware of the hissing, the refrigerant may be low. Other possibilities include a frozen expansion valve, a damaged AC compressor, or an unrelated engine vacuum leak.
Causes and solutions for car AC hissing
Regular Expansion Valve noise
It is crucial to remember that the expansion valve hisses and emits a certain amount of noise constantly. In essence, the expansion valve is a large space. The expansion tank is now in place to provide the refrigerant space to expand since it is leaving the AC compressor in a high-temperature, pressured condition. The process is naturally loud but decreases the refrigerant temperature, making it feasible to cool your automobile.
Naturally, the noise levels vary depending on the design quality of the expansion unit, your automobile’s sound insulation, and the expansion tank’s position. The fact that some persons will be more sensitive to the precise hissing sound frequency while others would not hear it further complicates matters. Therefore, it is probably simply a loud expansion tank if the noise is steady and the AC functions normally. For instance, there is little you can do to alter the fact that almost all Genesis models come standard with loud expansion tanks.
Low Level of Refrigerant
The expansion tank will become noisier with a low refrigerant level. Therefore, there is a potential the AC system has a minor leak somewhere if the hissing was not there before and particularly if your AC is becoming less and less efficient.
However, it is crucial to note that you should recharge the AC every year or two before you take your automobile to a repair shop to find the leak. Since the AC most likely lost a typical amount of Freon and only requires a recharge if you know it has been longer.
It is difficult to estimate how much the AC repair will cost if that is not the case and it turns out to leak. However, you should budget $100 for smaller leaks, such as those in pipes or valves, and it may cost as much as $300 or $400 if the leak is in the dashboard.
Additionally, a Freon detector may be used to find the leak at home, but working on the AC system at home is difficult without the right equipment. However, you may visit this site to learn what equipment you need and how to recharge the AC at home.
Frozen Expansion Valve
There is a chance of trapping water in the system whenever the AC is recharged. Therefore, a vacuum pump purge is required unless you add a tiny refrigerant volume. But sometimes, the AC may collect water, which can eventually freeze and jam the expansion valve.
Therefore, the likelihood that the system was not completely purged or that moisture was retained during the repair is significant if you have recently recharged your AC or even replaced part of the physical components. The best action in this circumstance is to recharge the AC system with new refrigerant after purging it. You will have to pay between $150 and $300 to complete that operation, depending on your automobile or the size of the AC system.
Broken AC Compressor
Even while a damaged AC compressor may create hissing sounds, it is currently the least probable reason. The internal gears of the AC compressor must fracture and break enough for a tiny piece to get through the AC pipes and block the expansion valve for the compressor to be the culprit.
The AC not functioning, compressor noises like grinding or rattling, or even the auxiliary belt breaking are all natural side effects.
However, if any of these signs appear, the compressor replacement is your last option to resolve the issue. Unfortunately, given that the compressor alone seldom costs less than $250, it will not be inexpensive. Additionally, the labour cost will be significantly higher, starting at $500. Additionally, you must cleanse and replenish the refrigerant, which will cost you at least $900.
Maybe It’s Not the AC
As we indicated at the beginning, the AC is not the only thing that might result in a little hissing sound in the cabin. In particular, vacuum leakage. A vacuum leak results when a vacuum hose connected to the intake manifold fractures. And the hissing sound is caused by air moving quickly through the breach.
Now, a vacuum leak will emit a mild hissing sound that sounds like it is coming from the dashboard; the sound may even alter depending on the engine speed. Opening the hood with the engine running and closely inspecting the intake manifold and brake booster, however, is the quickest method to locate the noise source.
However, a vacuum leak will also occur in addition to certain failure codes and other significant symptoms. An evident indication of a vacuum leak, for instance, is an engine speed that fluctuates at idle and increases while changing gears. Additionally, you will see fault codes P0171 and P0174 that indicate a lean fuel/air combination.
Now, if you can locate the noise source by listening, wonderful. If so, fix the fractured hose or connection, and you are ready to go. If you cannot locate it, you may take your automobile to a repair shop for a smoke test, which is about $50. You may also create your smoke tester. To find out how to click on this link.
Why Does My Car’s AC Hiss After Turning Off the Engine?
If the air conditioner in your car only hisses while the engine is off, there is a leak in the system. You must take your automobile to a shop to get the issue fixed so that they can identify the leak and replace the damaged part.
Why Does My Car Noise When the Air Conditioning Is On?
If your automobile produces noises while the AC is running, the AC compressor may be damaged. You will then hear a grinding sound coming from the engine compartment. Additionally, you could hear screaming if the auxiliary belt is worn out, and if you hear buzzing, there is probably too much Freon in the system.
What Noise Does a Faulty AC Compressor Make?
The most common sound of an unreliable AC compressor is rattling metal. But you may also characterise the sound as clicking, grinding, or scraping. In any event, you may listen for the source of the noise while the engine is running by opening the hood.
Why Does not My Car’s AC Cool?
There are several causes for your AC not to be cooling. The AC compressor clutch, the compressor itself, the system’s freon level, or a freon leak might all be to blame. Additionally, the system can be frozen or blocked.
How Frequently Should a Car’s AC Be Recharged?
It is preferable to recharge your air conditioner once a year if you live in a hot climate and use it all year. Recharging the AC, however, only has to be done every two to three years in more accustomed temperatures. Additionally, flushing the system every ten years is a good idea.
How Can I Determine My AC’s Refrigerant Level?
Unfortunately, without specialised tools and even then, it is not easy to check the refrigerant level in your air conditioner. However, if you are up for the task, you will find all the information you want in this article. The only option in such a case is to get your automobile repaired.
How long does the AC in a car last?
The automotive AC system, including its parts, is built to last a lifetime. However, you might anticipate the first problems to appear after roughly 15 years. In the meantime, you could have a rare freon leak, and you will always need to recharge the system every few years.
How Can an AC Expansion Valve Be Checked?
It is unsafe and difficult to test an AC expansion valve without specialised equipment or by removing it. Therefore, it is advisable to leave this task to experts. But once again, a hissing sound is the primary sign of a jammed or damaged AC expansion valve.
Conclusion
These two situations often occur if you just recharged or fixed the AC improperly, additionally if it has lately started to leak or has been over two years since your last recharge.
However, the AC compressor is probably ruined if the air conditioner is not operating and you hear grinding sounds. Finally, confirm that the noise is not originating from another source since engine vacuum leaks may also produce a hissing sound.
