I've lived with the engine vibrating since I bought the car 5 years ago until recently everything inside the car started rattling. I changed the engine mounts which improved the in drive, idle vibration, but now it vibrates during acceleration and at steady speeds. I bought tranny mounts at the same time, but haven't changed them yet since I read they don't really fail a whole lot. Another reason I changed the mounts is because it felt like the engine would bounce after shifting which it still kind of does. It also feels like it bounces when it's in higher gears at low rpm's. Anyway, I've cleaned the TB to where it looks like new and replaced a vacuum valve that had broken. Don't get me wrong - I can handle vibration at idle in drive, but what it's doing now doesn't seem like it's good for the car.