mbintx

Trying to get my new-to-me 964 sorted out, and I'm struggling to locate a mystery rattle. Driving over lane dividers or expansion joints produces a metallic rattle that sounds very much like a loose washer and nut at the end of a metallic rod or bracket. I've isolated the sound to an area around the passenger back seat. I've pulled the passenger front seat to clear out the area, but don't know where to go from here. It sounds like the epicenter is the rear passenger seat cushion, but that's obviously not it. If the rear seats were held in place by 4 bolts and nuts and all 4 were loose,and ratting, that's what this sounds like.

Any thoughts on what it could be?

JohnK964

I think your car is going to blow up soon I will take it off your hands 😂 Actually it could be the flapper valves the dump the hot air out of the wheel wells or allows it to come forward to the cabin. They are located in the area you describe. Just a guess though.

Dr Mitch

Along JohnK964's idea, can you hear the same sound when close your doors? If so, yeah, its the flapper valve.
I also recall a similar issue on a post a while ago - ended being the HVAC line from the engine to the front had a clamp loose or something.

mbintx

Interesting thoughts. But I really thing the rattle is coming from Inside the cabin...

Tmistry

Was the sound present before you pulled the front passenger seat?

Have you removed the rear cushions?

540964

A couple years ago I had some work done on my 90 C2 at a highly recommended shop in SE Michigan, also an advertiser in the local Porsche club monthly newsletter. Assembly work was the worst I've seen in 60 years. There was a nasty rattle that sounded like it was coming from inside the passenger side door, was finally traced to fasteners at the wing to cowl, where the rubber welt is installed. The shop had left those bolts loose and the large rectangular washers were rattling around. On top of that there were missing parts, sheet metal screws used, in fact they also cut off a piece of my LF inner fenderwell with what appeared to be tinsnips! I guess it was too difficult to install correctly so the guy must have just figured it easier to snip off the piece. The shop manager wouldn't stand behind their work, he told me "good luck restoring your Porsche." Worst experience I ever had with a shop that claimed to be "the best."

misterbeverlyhills

I had an annoying rattle inside, seemed like the rear passenger area too; it turned out to be the passenger seat belt buckle where the male clips into the female. The orange plastic release button rattles in some positions, you can manipulate it into a non rattle but it needs attention every month or so.

jevvy964

See if the passenger seat electric motors are wobbly, this can generate the sound you describe. Reach under the front of the seat (under the plastic cover if fitted) and give the motors a wiggle - any play you might have found your noise.

JohnK964

I would also check the seat belt retracting mechanism up under the self the rear speakers are mounted on

mbintx

1. It's not the passenger seat. The seat is currently out of the car and the same rattle is evident.
2. At times it sounds like it's coming from the rear portion of the center console. Will pull that next and see if something is loose under there.
3. I've used a rubber mallet to tap everything that seems obvious, to no avail. It "could" be the seat belt anchor point for either the passenger seat or rear passenger seat, but those are not easy to access.
4. Going over a bump, it sounds like a coffee can full of change sitting in the passenger footwell. But there's nothing there .grrrrr

JohnK964

It actually is pretty easy to accsess the retractors fold the seat backs down then there are 4 screws that hold the piece in one each close to the top and bottom on both sides😎 That is for the rear retractors Front one are probably harder never had them out

John McM

This is like playing a game of twenty questions. Is it the captive bars in the seat rails? You know the bars that the seat bolts bolt into?

Another possibility is coins under the plate under the seat base.

Tmistry

That's why I asked if the rattle started after the seat came out. The captive bars are the obvious culprit and it's not obvious if one doesn't know they're loose within the cage. This would sound exactly like change in a coffee can.

Rocket Rob

I would definitely remove the center console. When I bought my C2 coupe, I could see coins under the parking brake handle. I wasn't able to remove them with the console in place but was one I lifted it. If someone places coins in the tray below the parking brake and then accelerates, the coins can slip into an opening under the handle.

Rattles and noises in the car drive me nuts. Hope you can find it.

mbintx

Sooo...one of the captive bars (inside rear passenger seats) is MIA. So it looks like it could have dropped and slipped back into the crevice below the seats rails. Yikes. Any thoughts on how to search and retrieve???