I told the shop to replace my 2 engine mount and a tranny mount on my 85 300D. When I took the car in, the car was shaking like crazy, you can see the hood shaking and in additional to the diesel sound, you can hear the kong kong kong kong sound. Now, after I took it out, the car was like a gasoline car. It wasn't shaking, very smooth, and you can only hear the diesel sound (klaata klaata klaata). After driving around 10 - 15 miles, when I came to a stop light, I felt the car shaking again. It wasn't as crazy as before, where you can see the whole hood vibrating. Its just a little shaking. I opened my hood, the engine was shaking like crazy, but not the car. I looked at the engine mount, it seems like a boat, moving left and right.

What might be wrong? They didn't screw it tight enough? Or something else?