The answer to 'why is my pressure regulator making gurgling noise' is that a gurgling sound from a pressure regulator is often caused by a buildup of debris or sediment in the regulator. This can restrict the flow of water and cause the regulator to make a gurgling or bubbling noise.
Some common causes of this issue include mineral deposits, rust, or other debris that has accumulated over time. The gurgling sound is typically a sign that the regulator needs to be cleaned or replaced. It's important to address this issue promptly, as a malfunctioning pressure regulator can lead to water pressure problems or even leaks in your plumbing system.