2006 Ford F-350 4D 4WD Lariat LB
I got a Sinister bypass coolant filter about a month ago in my 2006 F-250 6.0 and now I am getting a hissing noise from the back of the engine, right where the outflow for the bypass is spliced back in. There have been no leaks and I even have a new filter on there - and still the noise persists. The sound dies down about 30 seconds after I turn her off. Definitely sounds like air blockage, but like I said, no issues, other than the hissing. Any ideas on what might be causing this?