'81 300D w/'84 engine/trans. So, the engine had been shimmying a bit at idle in the engine bay, and would only show itself when slowing down to a stop, at a stop, or shortly after taking off from a stop. My assumption: bad motor mounts. Get the two correct front ones (S11 hardness, Lemforders with Tri-Star logo on them), have a local mechanic install them and...shaking is worse than ever. You can clearly see the engine rocking back and forth in the bay, but even under slight acceleration (in park or in gear) engine seems to right itself.

Mechanic seems to think it is not related to the mounts, but possibly the injectors, because he thinks the car acts like it's "missing". His reasoning is that if a particular injector is fouled or faulty even in the slightest bit, that could be causing said issue.

Me? I'm not so sure he's correct. I think it's possible he may not have gotten the engine/trans lined up properly when bolting everything back down (perhaps). After all, the car is WORSE after the replacement. I also wonder if the transmission mount is bad, causing the issue.

Looking for everyone's thoughts here. Also would welcome recs for someone that's an old Mercedes expert in the West Central Illinois area, or at least someone within a couple hours drive. I think a second opinion would be a great idea at this point.

This is very frustrating, for sure.