Main Menu

Hissing sound and bouncy idle


Vehicle Information: Model (Boxster, Boxster S,Cayman, Cayman S): Boxster S; Year: 2000; Engine (type, size, modifications): Stock; Total Mileage: 135,000; Transmission: Manual;

I am hearing an intermittent hissing sound coming from the driver's side of the engine compartment coupled with a bouncy idle. Both Porsche dealer and independent shop don't know what it is did not want them to spend time to diagnose given the cost. Odd, because the hissing is quite loud. It occurs only when the engine is warmed up. With the car not moving, I blip the throttle and the RPM bounce around before settling. The hissing is sometime solid sounding, other times it is on/off on/off like Psst Pssst while others time is just is a solid hiss. I also noticed that it may be silent, but as I give it a bit of gas and start to let the clutch out, it will trigger the hiss. It does NOT trigger a check engine light. It has been doing this for about 1 year although the hissing is now loud and present most of the time - I only really notice it at idle possibly due to the engine being quieter and no road noise. Overall performance is NOT affected.

You must log in to view answers associated with technical questions. Join PCA to participate in our community.
No votes yet