My 07 w211 e550 is at 177k miles and i want an idea on when i should get my timing chain replaced. I get some vibration at higher speeds and i'm wondering if i just need new motor mounts but the timing chain doesn't seem like a bad idea at the milage my car is at.

 

More likely to be the engine mounts, gearbox mount, hardy discs, unbalance in your wheel/tyre setup, loose rubbers in suspension or subframes etc