I have been searching a long time for a solution and hope that you can help me. There is a hissing sound whenever I accelerate. The hissing occurs only in the initial phase of the acceleration. I can not detect from where it is originating. The volume also changes and sometimes it is louder than other times. Another item of concern is that sometimes my car feels sluggish, but other times it feels light and powerful. Do you know what is causing this hissing and the sluggishness?
Hi there, thanks for writing in about your 2006 Porsche Cayman. Generally, a hissing noise will come from a leaking vacuum source or something like an exhaust manifold gasket. The vacuum leak will cause some performance issues as the engine computers have a hard time regulating fuel delivery. If you would like to have this checked, a certified expert from YourMechanic can inspect the noise and perform any needed repairs.