Dan,
It could also be something that happens over time too. I always thought my engine was smooth throughout until I noticed it sometime last year before I even heard of the DMD. It seemed like all of a sudden it seemed rough starting around 3500 RPM. I had attributed to a vibration problem I had that was pronounced at idle. It turned out (according to the dealer) that my stab-o-shock had seized. After that was replaced, I still had the roughness starting around 3k rpm. Now with the DMD, no harshness.
George
