986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - HELP needed

ChrisZang · 04-22-2008, 08:05 PM

Hi,

when I replaced the air filter this weekend and started the engine with the engine cover off I noticed a LOUD hissing sound every time when I step on the throttle and also when I let off the throttle.

I did the usual tricks looking for a vacuum leak but couldn't find anything.

It seems to me that the noise is coming from the area which is circled red in the attached picture.

Any ideas / hints etc?
BTW: does anyone know the purpose of this big tube which is circled?

Thanks

04-22-2008, 08:05 PM	#1
ChrisZang Registered User Join Date: Mar 2006 Location: San Carlos, CA 94070 Posts: 1,450	HELP needed - Vacuum leak ? Hi, when I replaced the air filter this weekend and started the engine with the engine cover off I noticed a LOUD hissing sound every time when I step on the throttle and also when I let off the throttle. I did the usual tricks looking for a vacuum leak but couldn't find anything. It seems to me that the noise is coming from the area which is circled red in the attached picture. Any ideas / hints etc? BTW: does anyone know the purpose of this big tube which is circled? Thanks __________________ I still wave at Boxsters, but they no longer wave back :-( 2002 Boxster S "Violet" (sold but not forgotten) 2009 Carrera 4S "Kelsey" (current ride) 2015 FIAT 500e "Nikki" my commuter car Last edited by ChrisZang; 04-22-2008 at 08:08 PM.