It's going to be your door gasket. Listen to the earlier poster.

Sound insulation isn't really going to change it's effectiveness but rubber door seals shrink and allow wind noise. If gasket treatment helps at all, it's going to be a temp fix.

Replace the drivers side first and you should be see a big diff. Didn't notice your car but 300E's are around $60 a door I think.

Good luck

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Ken Fuller
1990 300E

The idea of focusing on the door seals resonates with me.

As I stated initially, I'm trying to get the interior back to the way I remember it: quieter than it is now. Adding Dynamat would undoubtedly do the trick (man, is that stuff expensive!!!); however, if I'm right about the gradual increase in cabin noise over the years, then it just makes sense that some OEM noise dampening material is failing. The door seals seem the logical place to start.

Most significant, in my case, is that a year and a half ago, a deer had the audacity/stupidity to leap the guard rail on the Taconic Parkway in front of my 126. It's hind quarters swung into my driver's side door causing quite a dent. (And if my 420SEL looked bad, you can imagine what shape the deer was in )

I have a great bodyshop up here that did an incredible job restoring the door; however, the comments you've all made lead me to believe that the doorseal may not be properly seated anymore.

Thanks for giving me something to tackle: Seems like an easy enough DIY job. I'll report back with the results.

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Eric

1991 560SEL-Euro (214,000 miles)
1989 420SEL (Retired from daily use at 325,000 miles; Use as donor vehicle)

Since you had a quite car before it was hit by a deer ( which is the #1 collison damage in WV) replace your door sills, but also check you're front door alignment. Concerning the care of the door seals, some people use silicone on rubber, but I believe there are better products, use a rubber treament product, its better for the rubber.
timreid

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timreid
1992 400E
euro lights
500E sway bars
210 16in wheels

Had some time over the weekend to start tackling the noise reduction project on my 420SEL.

The door seals all seem fine (quite flexible and snug); but nonetheless, I tried reconditioning them with some silicone to see if it made any difference. In a nutshell, it didn't.

Next step: replace the seals.

If that fails, I guess it's time time invest in some Dynamat...

Stay tuned!

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Eric

1991 560SEL-Euro (214,000 miles)
1989 420SEL (Retired from daily use at 325,000 miles; Use as donor vehicle)