The answer to 'pressure regulator making gurgling noise' is that a gurgling or bubbling sound from a pressure regulator is usually a sign of a problem. This can indicate that the regulator is not functioning properly and may need to be repaired or replaced. Common causes include a buildup of debris, a worn diaphragm, or an issue with the internal components.
If you hear a gurgling noise, it's best to have a professional plumber inspect the pressure regulator. They can diagnose the issue and recommend the appropriate repair or replacement. Attempting to fix the regulator yourself may lead to further damage if you're not experienced with these components.