I kinda wonder too. Maybe it's the odd-number of cylinders? Isn't the I-5 just intrinsically less well-balanced compared to the I-4?

My first ever 240D experience was when I looked over an 82/83 240D Automatic. The car had 310k mi.

It definitely sounded different to my 617. The 617 sounds ... like a 617. It has a weird off-beat 'rythm' to it. I could tell apart a 240D from a 300D on the road just by the engine sound...

The 616 also seemed to transmit more of that 'steady' vibration to the chassis. However I think it was that particular car's engine mounts that were just bad.

If I'm not wrong the earlier non-turbo 617's didn't have the rack dampener either.

kinda makes me wanna talk to the designer of these 'amazing' motors...

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2008 BMW 335i Coupe