Back to all

Your Vehicle's Hissy Fit (AC System)

August 20, 2023

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.  

Sterling Tire & Auto
34701 Van Dyke Rd
Sterling Heights, Michigan 48312
586-264-7775

Need Service?

Request a Quote

More articles from Sterling Tire & Auto

No Shake, Just Smooth

September 6, 2026

When your vehicles wheels are out of balance, theyll likely give you some clues. Your steering wheel might shake, the floor or seat vibrates and you might find your vehicle pulling to one side. Other signs? Your tires might wear unevenly and may make odd noises. Plus, fuel economy might not be ... More

Catching Trouble Early

August 30, 2026

Your vehicle depends on wheel bearings. Sitting between the wheels hub and axle, they allow your wheels to spin smoothly, bear the vehicles weight and work in harmony to stay aligned with other parts. Wheel bearings can fail in several ways, and they may send the driver some pretty clear clues... More

The Car Fluid Most Drivers Forget—And Why It Matters

August 23, 2026

Heres an automotive part you might not be familiar withthe differential. Its a component that transfers power from the driveshaft to the wheels. Its called a differential because the left and right drive wheels travel at different speeds when you make a turn. During that turn, the wheel on the ... More