Back to all

Your Vehicle's Hissy Fit (AC System)

January 7, 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 Tire & Auto Service Center Waukesha
S31 W24721 Sunset Drive
Waukesha, Wisconsin 53189
262-513-9500

More articles from Tuffy Waukesha

For 4x4s (Maintenance of 4x4 Vehicles)

April 27, 2025

Some people love 4x4 vehicles, the true 4-wheel drive works of engineering like Jeeps and 4x4 pickups that allow you to seemingly go anywhere on the planet. You can climb up a 40-degree rock trail with some planning and skill (always careful to protect the environment, of course), or you can get ... More

Not a Good Vibe (Driveshaft Failure)

April 20, 2025

When you feel your vehicle vibrating as you're driving down the road, one cause could be something you may not have ever seen: your driveshaft. It is underneath the vehicle and most drivers don't climb under there to take a look very often. The driveshaft is a cylindrical part that helps conduc... More

A Door No One Can Step Through (Fuel Door Repair and Maintenance)

April 13, 2025

Your vehicle has lots of doors including that one usually near the back on the vehicle's side. That's the fuel door, something you use every time you gas up. These endure hundreds of open-and-close cycles, usually without any problems. But when they act up, it can be a major inconvenience for ... More