Just mounted the new Bilstein's on my S350 and ride is still the same?!
 

After the ride of my s350 got real bad lately, I mean real bad, I could almost feel every bump or hole in the road, I decided to get bilstein HD's.
Just replaced them today and I'm not to happy with the ride.
Recently I drove a 190d and wow the ride on that thing was good.
I'm also pretty sure that the ride of my benz wasn't like this three years ago when I got it.
The old shocks (also bilsteins, I thought they were sachs) were probably in the worst shape they could be.
The ride now is better than with the old shocks but still isnt what it used, or its suppose to be.

What happens is when I go though holes and bumps you can hear a pretty loud noise and there is very uncomofotable rattle.

What can this be, or, what am I looking into here?

Thanks

How old are your tires? You should also replace the front/rear sway bar bushings and links if necesary.

Tires have less than 2k on them. 235/50 R18 pirreli scorpion str.

You could have a lose bushing. W140's are hard on their suspension and it wears accordingly. Also Bilstein HD's will ride stiffer then Comforts. MB's OE shocks are softer like Comforts.

It's time to put the car in the air and do the 4 P's; push, pull, pry and prod on all joints to find the looseness and correct it.

Good luck,