Hey, all,

I know this is a much-discussed topic around here, but I'm hoping someone's been through this, or might have a logical way for me to check it out. A search availed me nothing.

Car: W202, '97 C230, 68K. Great condition; very quiet inside -- except . . .

. . . when I run over those ripple-bumps. You know the sort of thing -- concrete, with the little waves set just close enough that they set up a resonant vibration in your cabin. I hear it nearly every morning on my commute across the rough surface of the Miss. River bridge, esp. if the A/C is on and the windows are therefore closed. It's faint, I admit -- if I'm playing music instead of a talk station, or if the windows are slightly open, it's hard to detect -- but it's there, and I know the car didn't do this when I bought it a year ago.

Speed doesn't seem to matter -- I hear it at 35 as well as at 50, if the road is bad. Tires are at 30/34, but I heard it even at the recommended 28/32.

The A/C cabin filter has been replaced, and its retaining panel and clips are tight. Nothing seems to even flex in the dashboard/console area. The noise is not metallic-sounding, and taking things out of the glove box before a drive doesn't prevent it. I'll try driving with windows up and A/C off for a while tomorrow morning (and in this heat and humidity, that's a sacrifice) to see if it might be the A/C system. (Could it be a wheel balancing is needed? Car drives beautifully on a smooth road.)

Has anybody else had this happen on a W202? There are so many rough, ripply patches in what are laughingly called streets around New Orleans that it's a pain to live with. What could I look for? Or would my mechanic have to dig into the dash?

TIA!

__________________
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-- Paul W. (The Benzadmiral)
('03 Buick Park Avenue, charcoal/cream)
Formerly:
'97 C230, smoke silver/parchment; '86 420SEL, anthracite/light grey; '84 280CE (W123), dark blue/palomino