Back to all

Your Vehicle's Hissy Fit (AC System)

June 30, 2024

When you hear hissing sounds coming from your vehicle, you might start thinking the worst.   One type of hissing coming from around your air conditioner may be a normal sound, or it could be a sign of serious trouble.

First - the normal sound.  When you turn off your vehicle, the refrigerant goes from its high-pressure side to the low-pressure side. Some of those noises are normal.  But when it hisses all the time, that's another story.

One cause could be that the refrigerant is leaking.  Air conditioners are fairly complex systems that involve various pumps, hoses, valves and motors.  When your air conditioner is cooling, the refrigerant changes from a gas to a liquid and back.  That refrigerant is under pressure, and there are many places it can leak from. 

A hissing sound can also be a failed valve in your air conditioner's compressor.  It is what controls the refrigerant's pressurization.  It's important to have this fixed fairly quickly after it develops a problem because when it isn't, that can lead to more extensive—and expensive—repairs.

If you hear screeching coming from your air conditioner at the same time you hear hissing, your compressor may be on its last legs. It could also be a defective clutch. 

Any time you hear a noise you haven't routinely heard before, bring your vehicle to us so a technician can check the various components and properly repair the problems.  Air conditioning systems are complex and are best handled by a professional with the right tools and equipment.  When your AC has a hissy fit, let us cool it off and you at the same time.  

Tuffy Pelham
3422 Pelham Parkway
Pelham, Alabama 35124
205-624-2190
http://www.tuffypelham.com

More articles from Tuffy Pelham

The Key Won't Turn! (Ignition Problems)

February 15, 2026

You've just arrived at the store shopping and you're ready to head home. You put your key in the ignition and oh, no! The ignition won't turn! What do you do now? Don't panic. There are some things you can do to get going again. The first thing to do is see if you have a locking steering wheel... More

When Your Tires are Tired (Tire Replacement)

February 8, 2026

Tires are so reliable these days that few drivers pay much attention to them. But tires wear out. They have a tough job since they are the only point of contact between your vehicle and the road. They have to get your vehicle going from a stop, keep it going, make sure it is headed in the dire... More

Cruisin' on Down Main Street

February 1, 2026

When automakers first came out with cruise control, it was a real luxury item. The older cruise controls used a mechanical vacuum system but it worked. Well, some of the time. Now days, cruise control is all electronic, thanks to computers. It's reliable and a real convenience on long trips. ... More