My E320 has a heart beat! IT'S ALIVE!
There's a steady bump . . . bump . . . bump coming from under the dash. In my old 86 300SD I would say I have a leak in one of the diaphrams that control the HVAC system. Do the new cars use the same system? Has anyone else hear this noise in theirs? It's getting louder. I only hear it at idle, once RPM's get up it goes away.
IT'S ALIVE . . IT'S ALIVE!