1995 Carrera Rattle Mystery
 

I recently bought a 1995 Carrera 4. It's a lovely car and excellent mechanically, but there's one small issue that I can't figure out - a rattle that seems to be coming from the rear deck, or maybe the spoiler. It can only be heard on very bumpy roads. We've looked at everything obvious back there and it all seems to be bolted up and snug. All suspension components that were worn - including shocks and bushings - have been replaced. Any ideas/thoughts appreciated!

Random thoughts....
Metallic or plastic sounding?
Same exact noise each time or slight variations?
Check the inside rear deck cover where the speakers are (just 2 or 4 screws that keep it in) and make sure all is tight and push down on it to make sure speaker backs aren't hitting something.
Does it happen with the spoiler up or down? Try both on same section of road, using switch on center console to run spoiler up/down if needed. There are a couple of rubber stops that may be worn out when it is down.
Also check spoiler (and engine compartment) for any loose bits that can wack into something and cause your noise.
Rear decklid rubber bumpers on back corners are screw-in (Its a little known fact, Normie) and if you screw them out a bit, will push up on the latched rear decklid, keeping it from rattling/moving IF it is related to the rear decklid. Can you safely drive that section of road with the rear deck open to eliminate that suspect?

Semi related....if your car has been suffering with FDS (floppy deck syndrome), installing new decklid rubber bumpers and deck shocks, and adjusting the decklid bumpers so they were tight left me with a rear decklid that, when you pull to release it, acts like it just took a fast-acting Viagra.
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Keith I'm not in the market for another car, but that is some great advice and if anybody was looking for a car I don't think they would find one more sorted than yours.

Those are all terrific suggestions -- thanks. We did unscrew the rear deck and looked in there but couldn't find anything. I'll have another look with all this in mind.

Thanks! But if you only knew.... :) I've got a fix-it list a mile long....but its fun to do.

IF I can now actually contribute meaningfully to RL993, its all thanks to the folks here teaching me a thing or two over the last 5+ years. :cheers:

I had a rattle that only could be heard around 60mph, which is difficult to diagnose when you typically drive alone.

In any event, it turned out to be a fender liner screw on the passenger side rear well that was tapping on the rear fender. I wound up grinding the tip of the screw down so it didn't protrude so far and hit the wheel well. I could kind of replicate it, but tapping on the liner which caused the screw to tap the fender. took me months to figure that one out.

Check exhaust area for something loose
 

Check the heat protection plates. These are the heat shields that cover the pipe between the catalytic converter and the mufflers. One of mine rusted through at the attachment points resulting in occasional rattling. I got a low pitch rattle that was barely audible over the sound of the engine.

I recently purchased a 993, and had a similar experience. There was a metal-on-metal banging sound that seemed to be coming from the passenger-side rear suspension. At first it seemed random, but I eventually discovered that anytime I unloaded the right side suspension, I would hear it.

I checked under the car and the engine bay and couldn't find anything loose or any sign of metal-on-metal contact. We pulled most of the rear suspension while changing the springs and again, no sign of anything amiss. But the noise persisted, so I resigned myself to having the mechanic find it.

He did find it -- an aluminum can stuck under the passenger seat (seat had to be removed). To track down the noise, he had to have someone else drive the car while he moved his head around trying to locate the sound. It is amazing how sound can be tricky around a car.

Full story and photos here: http://twofourthsfull.blogspot.com/2...nsion-fix.html. Given the big lipstick mark on the can, I'm glad I started complaining of the suspension noise to my wife as soon as I got the car! :-)

Funny how these things can be both annoying and interesting at the same time. My mechanic went over the car again - checked the bushings, muffler clamps, rear deck, spoiler and so on - the mouse eludes us. It's not bad because the rattle is low-pitched and can only be heard on bumpy roads - it's not speed-related and doesn't show up on any decent pavement. I think I'll check the heat protection plates next - thanks to all.

There are two heavy metal tabs that are part of the seat belts blockage, under the top of the deck lid, in front of the speakers, check them out.
and for the engine lid:
Open the rear spoiler with the console button halfway.
Check the bottom left and right corners on the engine lid from outside, where the spoiler rests.
Does the paint look scratched ? If so you need to add a shim to the spoiler base to raise it.

Also, with the engine lid closed, try to pry with your fingers through the bottom of the lid and move the lid up and down. If there is play, open the rear engine lid, on the rear lid itself, left and right, there are two rubber grommets . turn each counterclockwise to make the lid close snugly against both grommets.
If lid is already snug, open it and try to shake it up and down, to omit any noise from it.

I had a rattle in the rear suspension area once too. I located it to one of the little screws that holds the fender line in place. The backing had come off and it was slightly hitting against the fender, causing the noise. I put a little rubber cover on the end of the screw and noise was gone!

Sway/roll bar links? That was the cause of the rattle/knock on my daily driver Honda.

The only noise I ever had from the rear on my 993 was from the fasteners that attach the front and rear halves of the plastic fender liners as they rattled against the inner surface of the rear fender. A strip of closed cell foam attached to the inner surface of the rear fenders at those points, solved that issue.

Mine was rear fender liners also on my '95 coupe .. there's a factory tsb no less showing how to remove them and place plastic channel along the outer edges to snug them up. I used a length of small diameter fuel line and split it on one side, cut to length and stuck that on, it worked like a champ and looked just like the factory photo :-P

You might want to check your rear windshield, had a rattle creaking sound silenced by lubing around the rear windshield with Pedro's wax. If this is the cause, you might need to re-apply the Pedro's wax if the noise returns or there is also a permanent fix using the factory "rope" fix.
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'97 blk/blk C2S

I chased a similar noise for almost two months before I discovered that the left rear fender liner had somhow become misaligned and was bumping against the fender. I loosened all the screws and then tightened them from the middle out to each end...Problem solved.

Terry