Well, this was the reason why i sold and replaced my previous car after replacing everything for almost no improvement and pulling my hair for over a year. And here i am dealing with this over again on my W210. I don't know, maybe the previous car created a trauma...
The symptom is a mild diffuse vibration and harshness that starts around 90 up to around 120 kmh usually (around 60 mph). I can't say i have a bad vibration or shake in the steering wheel, maybe very slight at times. It is intermittent and sometimes disappears for a few seconds, can't say if it's related to the asphalt or something else. I don't feel like it's worse under load. Wheels are torqued correctly to 110 nm and playing with inflation pressure has no influence on the vibration.
Tires: Yokohama BlueEarth 215/55R16, 7000 km.
Rims: Stock, look bad and corroded but don't appear to be bent visually.
Flex discs: No cracks at all, probably original to the car, original MB parts.
Carrier and driveshaft bearing: Can't say because of the heatshields but no symptoms of it being bad (heavy knocking under accel at low speeds/take off and vibration worse as speed goes up).
Motor mounts: Look perfect, original MB part.
Trans mount: New, original MB.
Rotors: New, no vibration when braking.
Front suspension: Everything tight except for a very slight play in a tie rod or steering ball joint. New sway bar bushings and links.
Dealing with vibration is the most frustating issue i can think of with a car, drives me absolutely mad! Any help appreciated.
