I mentioned this is another thread - but as we all hate interior nuisance rattles, I thought I would start another thread on the topic!

I recently took delivery of a really clean and well sorted 2008 997.1 C4S. I bought it from a well known member of this site.

I am loving the car so far, and smile every time I see it in the garage, and am absolutely having a blast driving it. The PPI w/ bore inspection came out clean, and the cosmetic condition is even better in person.

Nuisance interior rattles are the bane of my car ownership existence, and I want to track down 2 I have noticed so far. One is coming from the passenger seat area but can not tell if it is the seat, the belt area, or the back seat - any advice would be appreciated, but it seems like it will be easy to rectify, but is also not overly annoying.

Secondly, I have a rather annoying interior ‘buzz’ that I get when driving on imperfect roads. The car has a passport radar detector that I am going to have removed, and I wonder if it is an unsecured wire the is resonating, but any other suggestions or thoughts would be appreciated. I have attached a very clear video of the rattle:

 

2009 C2S 194K miles

You may try shaking your car with your stereo... from another thread: https://rennlist.com/forums/997-foru...l#post18085340

Here are two videos I made of me shaking the cht out of the interior to find a buzz; in this vid, I use an audiophile CD with an inventory of tones at various frequencies: https://goo.gl/photos/zG3KY99vDUNefhBc8
If you have your phone connected to the stereo, you can use the tone generator here: https://www.szynalski.com/tone-generator/

From an older post of mine:Peace
Bruce in Philly (now Atlanta)

 

This may or may not help. My seat rattle on my 991.2 was from the seat latch that moves it forward. Landed up sticking a piece of card in (and stopped using the latch). Had a buzzing from the drivers seatbelt too on my 997.1. Stripped the part on the B pillar and stuffed it with pieces of felt tape (harness tape). Was fiddly putting it all back together but problem solved.

 

When driving, watch the empty passenger side seat back and see if it's vibrating or bouncing at all. If so, that's usually caused by irregular wear on the rear tires, like cupping. Stock suspension settings on a 911 have quite a bit of camber. Also, get your head down to floor level behind the car and look at the inside 2"-3" of each rear tire to see if they're worn. If you have vibration from tire wear and eliminate the vibration, you'll eliminate the noise.

Also, quite a few of the wires behind the dashboard have foam around them so they don't make noise when they vibrate. If someone has been in there and moved their position or removed the foam to splice to a wire, they could now be making noise.

....or upgrade the exhaust and enjoy the song from the flat 6 which will also make the other noises disappear.

 

Thank you! These are great ideas, I have never thought of the audio frequency to find a rattle, great idea! I do not think my car has an AUX-in, but maybe I am not looking in the right place.

yes, I am noticing the passenger seat vibrating / moving at speed. The rear PASM struts were replaced very recently, could the rear end require an alignment? I have not checked the tire wear yet, but that’s my next course of action.

 

If rear alignment is out of spec, or even in-spec with older tires, tire wear can definitely create a vibration that causes things to rattle that otherwise wouldn't if the car was rolling smoothly. Take your palm and rub it over the inner edges and outer edges of the tires in the direction they curve (circumference not across the top of the tread). See if the tread blocks feel sharp in one direction or if the tire feels like it has rhythmic small mountains in the tread (cupping). If there is still good tread left but you feel sharp points on either the lead edge or trailing edge of all the tread blocks, then swap the rear tires around (left rear to right rear and vice versa) and that will smooth out the tread after some miles. If they're cupped, there's no fix for the current tires and they need to be replaced. When installing new tires, have the alignment checked and have the alignment shop reduce both the rear camber and the rear toe (they need to leave some of both for handling predictability) but not as much as the factory spec unless you're tracking the car and need every ounce of grip. Making that alignment change will add 50% to your tire life (rears that lasted only 8-10k miles will now last 12-15k miles).

 

I had exactly the same on my 997.1 C2S cab with turbo style seats (with the hard cover). Used one velcro pad (the softest side of the velcro) at the bottom of each cut out for the lever in the cover. When not used, the lever falls over the sticky velcro pad, so you do not notice at all. This has significantly reduced the lever rattling.