My leather seats make the most noise in the SE.

I've often wondered about stategically placed exhaust to body brackets. Maybe re-introducing the vibration into the cab 180 degrees out of phase with the ambient noise such that the noise is cancelled/reduced.

Agreed. The SD's seats are miserable because they are relatively stiff. Even the SDL seats, which are softer, exhibit the characteristic ticking sounds that simply won't cease. The only solution is the music........

It's been a while since I checked this so I will answer the last few questions.
Arminski, I purchased 1 sheet of insulator 5 ft long (it comes either 3 or 4 wide) can't remember.
Probear, As far as the wind noise around the pillar goes, I had some and tracked it down to the A pillar. Removed the trim on the inside between the door and windshield and filled the hollow openings with expandable foam....huge difference....very quiet now. You could probably do the same to the mid door pillar as well as it is hollow also. As long as you don't have a water leak all should be fine for years to come.
Yes my seats make some noise also....goes with the territory of old hard leather, it is well within a tolerable level and the radio makes it non existant.
Whiskeydan, Ypu are right...exhaust vibrations are brutal at highway speeds. I had sprayed the entire exhaust with a very thick coat of the "firewall" product from 2nd skin. This has drastically reduced all exhaust noise and vibration. I don't know how long it will stay adhered but so far all has worked out great and it's been a few thousand miles.

Hello, I have read and re-read your posts on sound proofing. Thanks for all of the great information! I went ahead and spoke with the guy at Second Skin and ordered some of the coating product you used. I was wondering, how is it holding up in the areas you applied it externally, like the underside of hood, the exhaust, and underside of the car?
In fact, a general update on sound performance, deficiencies and or improvements you have made subsequently would be great if you have time.

I did a similar project that may be useful in documentation. Search my posts or google 84 300TD soundproofing.

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84 300td (Yes, a wagon)
"The Golden Dragon"
195k, 2nd owner
Lives in Redmond, WA

How about going with some taller ( lower numerical) differential gears? You could lower engine rpm, and presumably engine noise by swapping in a diff from a gasser.

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1982 300SD " Wotan" ..On the road as of Jan 8, 2007 with Historic Tags

Cool thread. I like what you did!!

I have been playing with the idea of that "stuff in can". Pulling the interior and rolling it on everywhere.

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AJ

1985 300D (SOLD)

This thread reminds me of this story:

http://www.snopes.com/business/genius/spacepen.asp

The reason I say that is because I once had to drive 500 miles in my 240D with a good sized crack in the exhaust manifold. The cracked manifold of course made the car uncomfortably loud. Solution: I wore earplugs.

When I drove that car on a 5000 mile road trip (after replacing that exhaust manifold), I brought ear plugs along in case the car's noise level over consecutive 10+ hour days started to bother me. I ended up not using them.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

For you guys with rubbing seats...it may not actually be the seats, but where the door panel meets the door sill. On every W126 i've owned, this was a big problem, and make the driving experience annoying to say the least. I remedied it by putting adhesive-backed velcro along the sill. Worked like a CHARM. Looks stock too.

As for the wind noise around the pillars...I remember hearing something about dealers slightly bending the window frame inward to fix this problem.

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

I am worried with all those layers, potentially unrustproofed self tapping screw holes, layers of jute, etc., that water may build up in locations where it shouldnt and cause premature rust...

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (116k)
1991 350SD (206k)
1991 300D (228k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (267k)

Past Diesels:
1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k)