jw97C2S

Has anyone who has lightened their 993 experienced substantially increased noise emitting from the back seat area (sounds like alternating hissing/sucking noises). I just removed the rear fold down seats, all rear seat belts, spare tire, trunk carpeting, windshield washer reservoir/motor. My guess is that it may be coming from the rear seat belt bolt holes but I'm not sure. It is a 1997 S. Any ideas?

Thanks for any help.
Jim

My Q Ship

jw,
Just a couple of quick questions...do you have some sort of sport air filter system on the car? Does the noise vary with more or less throttle input? I'm thinking that if you have a "free flow" air filter system that noise you are hearing is the air being sucked into the airflow meter. The air filter housing/airflow meter assy. is just inches from the right side of the rear firewall and with the rear seats removed it is just easier to hear all these wonderful noises.
Q

jw97C2S

Thanks Q. Just have the optional motor sound package (drilled airbox/mufflers). I should have said that the noise becomes severe at full throttle. You may be right about the removal of the seats causing the noise. If that's it then I'll just have to live with it.

Thanks again.
Jim

Dbltime

Jim,

I had the motorsound package and stripped interior. The air sound is exactly as you describe. I now have a cup air box and the sound is louder yet. Add the Fabspeed exhaust and you will not notice the air intake noise.

DJ

Yep, my car does this too.

I thought that it must be air getting sucked through the seat-bolt-holes. Bill's right: put the Supercups on, and you won't notice that sucking sound.

Joe@Fabspeed

after you removed that much sound insulation and sound deadening material........your Porsche mufflers now allow you the hear the engine sucking in air thru the airfilter housing. I like the whistle and instaneous whistle & sound that is electrically connected to the gas pedal.

jw97C2S

Thanks for the help guys. I replaced the rear seat belt bolts/rear seat bolts with plastic screw in caps (from Ace hardware) and the sucking/hissing is gone. I wouldn't mind increased engine sounds but the sucking/hissing noises had to go. Thanks again for the help.

Jim

johnsopa

Hi Jim. I just took my kids for a weekend away in my C2S and they were complaining about the same noise you're talking about. Can you elaborate on which holes you plugged? I took out the seat backs to get more room for their car seats, but of course, the seat belts are still in.

Thanks,

John

jw97C2S

Hi John
The local hardware store (Ace Hardware here) has small threaded black plastic caps (similar to a bolt but plastic) which you can use to thread into the rear seat bolt holes. I believe the hole size is 5/16. I cut a small groove on the top with a dremel so I can screw them in tightly with a screwdriver.
Good luck
Jim