Stratford Auto Repair

A properly working car A/C system is meant to run smoothly and quietly. So when you hear a hissing noise, especially when the A/C is running or immediately after shutting the engine off, it’s a clear signal that something might not be right. This sound might be harmless—or it might be your first warning that a leak or pressure issue is affecting the system’s efficiency. Let’s explore what causes this hissing noise and what you should do about it. Normal vs. Problematic Hissing Sounds Not all hissing sounds from your A/C system mean there's a malfunction. In some cases, a slight hiss is normal. After you turn off the engine, you might hear a gentle hiss for a few moments. This is typically the refrigerant equalizing pressure between the high and low sides of the A/C system. It happens as the system cools down and the refrigera ... read more