It's not the most refined engine in the world by a long shot. Out of spec valves, marginal injectors, worn or poorly fit drive belts, and intake/exhaust gasket leaks add to the cacophony of strange and wonderful sounds that can be heard from two blocks away when a B230F is at idle. Throw in some mild piston slap and heads turn everywhere you go. Real driving excitement, and it's still more reliable than a new Pontiac.

I think that most of the cabin noise at speed can be attributed to poor soundproofing. Also, the motor and transmission mounts in 200 & 700 series cars transmit an unacceptable level of vibrations for a "luxury car" (or at least one that was priced in league with American luxury cars of the time), even when they are fresh out of the OEM box.