My 1984 300D-T has the smoothest idle of any 300 I've owned (this is my 3rd). Except-after driving at highway speeds and coming to a stop, the entire car rocks like an old truck. I have changed all the filters and fuel bleed lines. The car has new engine and trannie mounts, and starts perfectly. The car does seem to smoke quite a bit. 202K miles, and major oil seals have been replaced. The car uses no oil at all (.5 quart in 3K miles). Noticed fuel smell coming from engine, tightened lines. On the highway the car gets up to the 100degree mark, running cooler in town. The shaking is only after the car idles after higher extended RPM's. MPG: average 24. EGR vacuum line is plugged (was told to do so by mechanic), have run 3 tanks of Redline Diesel Catalyst through. Good power, but tired of the "shakes" and smoke.