it sure sounds like my intake has a vacuum leak. spent the morning removing the plenum to reseal the plenum to the base. and checked all my hoses and conections to the intake. all look great. maybe this hissing is normal for this intake. no real performance issues. just sounds much louder than my buddys tpi gta.

anyone out there experience this. the only other thing i should check is the base.

 

Have you sprayed a crap load of carb cleaner all over the motor to check for a leak? Also by the look of your avatar it looks like you have a CAI type deal, is there a cone filter on the end? Those can make a good amount of noise. What about an exhaust leak maybe the headers/heads or headers/Y.

 

good points! thanks for all the help, turns out it was an injector that has a missing clip to retain it in respect to the fuel rail. i just moved it around a little and noticed a change in noise. for the time being a paper clip and gasket maker are solving the problem!