996 Cab interior noise fixes

Last month the wife and I took our 02 Cab up to Portland for Parade, and then took some time to do some sightseeing along the Oregon and Northern California coast. While the car performed magnificently, and returned a 1300 mile trip average speed of 62 mph and fuel economy of 26.8 mpg, interior squeaks, rattles, thunks, etc. made for a distraction and lessened the enjoyability of the trip. Most of the noise was on less than perfect roads, and in driving situations that required complete concentration. My wife was not able to help find the noises while on the trip, because most of the time she was holding on for dear life! This last long weekend gave me some time to hunt these gremlin noises down, and I am happy to say that I have been able to terminate with prejudice the majority of the noises and that the car is 100 times quieter, and feels much more solid. Chances are that many of you have the same noises, so I thought I would share my findings. 1. High frequency door squeak from low frequency road vibration or tar strips. This one was the most annoying, but turned out the easiest to fix. The squeak was coming from a metal alignment sleeve on the outside rear mirror. This little brass sleeve is used to help center the mirror in the housing. To get to it, pop off the mirror from the housing, ( it is just held in with plastic fingers) and give the sleeve a good dousing of silicone lubricant. 2. Clunking, loose bolt sound when hitting road irregularities. This one turned out to be the sunvisor mounts in the windshield header. Each sunvisor is held in with two torx screws, and they had managed to back themselves out and were very loose. The sunvisor mount on a Cab is also the left and right alignment and mating points of the convertible top, and could be why they had come loose. I applied loctite to the screws and re-tightened them. Since this is a high stress point on the car, it is understandable that these screws came loose. I recommend that everyone with a cab verify the tightness of these screws. 3. "thumping aluminum pan" noise from under the drivers knee bolster. This is the panel under the steering wheel. This panel is soft aluminum covered in leather, and is next to a structural dashboard member. The flexing of the chassis can cause the two to hit, and it sounds like an cooking pan getting hit with a spoon. The solution for this was to stick some 5 mil packing foam sheet between the two pieces. With this insulation, no more noise. 4. Loose "user-installed" wiring. If you have added any wiring for things like a garage door opener, ipod input, footwell lighting, radar detector, etc., make sure that it is fastened securely with wire ties, tape, etc. It is amazing how loud a noise a piece of unsecured cable can make when the car is going down the road. In my case, I had several wires running down the drivers A pillar and under the dash to the center console. Until I secured them down with wraps and tape, they were making quite a commotion. If you have other noise canceling fixes that have worked for you, share them with the rest of us.

Thanks for the info Gary. I don't have any of those noises yet but I'm sure that they will eventually show up on my cab too, especially with the new m030 suspension kit and the resulting stiffer ride. Perhaps your new suspension may have contributed to the recent noises as well.

28.6mpg/???! and from a cabrio? is that really possible?

Thanks for the fixes, I've noticed my Cab getting slightly squeekier lately, I'll check these out. Also I drive solo a lot and notice my passenger Sport seat back seems to ralttle at times, anyone know a fix for this?

No, 26.8 mpg. don't tell me, you also believe in Dog?

I think he said 26.8, not 28.6 - definitely possible if you're not in stop and go traffic.

My thought as well. Now after a few thousand miles, it is fully settled, and does seem a little stiffer. Not bad, just stiffer, and there are certain road conditions that boom through the cockpit. All in all, today's tighten-up was a real refresher.

I fixed a buzzing rattle in the front left area of the dash the other day. Turns out to be the speaker cover on the dash, had to tighten the screws. I tightend the screws a second time after the noise reappeared and now it's gone. A little concerned if something will crack under the hot sun with the screws so tight!? The other one was the passenger seat belt "catch" (on the side of the seat). The seat belt buckle was squeaking against the "catch", I sprayed some teflon lubricant in it and fixed that. Then there's this loose metal sound when I sometimes go over a bump, sounds like something under the engine bay. I thought it was the exhausts... Turns out to be the license plate/frame holder knocking against the bumper cover. Dampened all contact surfaces with those little small adhesive sponge pads (don't know what you call them!) I think I have some rattle occasionally in my sun visors, thanks for the tip, I'll have to take a closer look at them.

Actually, I've averaged 29 MPG in my cab from Richmond to DC, but that was driving like a granny after I had just received a ticket. Also, this weekend I averaged 26 MPG and change with an average speed of 77 MPH from Southern NJ to DC. Of course this is based on the OBC, which some people consider totally inaccurate, but I believe it.

Used to get that (26.8 not the ohter) on trips in my Boxster all the time. However, on my Banzai run up from FLA in the 996, I only got 22-23.

Tighten the proper amount, but put something like Loc-Tite, or a similar product on the threads before you do. That ought to hold a screw in a plastic fitting like that.

Thanks for the post.

Has anyone ever done anything to stop the door/window/roof seals squeeking when its cold ? Is there any lube/treatment for these seals ? The door seals look like they have white marks where they have rubbed togther. I really noticed the squeeking today after reading about all the fixes you guys have done. On my NSX the dealer used to put what looked like vasaline on the Targa roof seals (a real mess by the way)

I used to get an extremely annoying high pitched squeaking where the door meets the rear quarter, so basically right behind my ear. Shined it up with some 303 Aerospace Protectant and that took care of it.

every 3 months, I take a clean piece of paper towel, wet it with silicone spray, and lubricate and clean all of the rubber gaskets/seals on the top, including the windshield header gasket. This allows all of the seals to slide on their mating surfaces without any noise. You will be amazed at the amount of road grime that accumulates on these seals.

OE - Every 3 months???? Now let's be honest here! With you, it's probably every 3 DAYS!