Good Evening people..... Changed my fuel filter tonight which was a pain to get off. I even had to snap the juiblie clip but a few tie straps sorted that out..... Anyway even after a long idle and a quick run, there is a hissing noise coming from my injectors. I presume it's trapped air being released from the system but has anyone ever had this problem? It's not constant but comes and goes and stops once revved. No running issues and drives ok. And also no warning lights. Is it bursts of trapped air coming through or is it something else?