Motor mounts serve an important function: They support the weight of the engine and transaxle (or transmission), and also isolate engine vibration from the rest of the chassis. With so much emphasis on controlling noise, vibration and harshness in late model luxury vehicles, it was inevitable that sooner or later motor mounts would go electronic.
Most motor mounts are relatively simple in design and consist only of metal attachment plates and large rubber insulator blocks. But, some vehicles have “hydraulic” or “hydro-mounts” with hollow chambers filled with glycol or hydraulic fluid.
Often-overlooked engine components that may need to be replaced when installing a remanufactured engine are motor mounts. These rubber mounts can deteriorate, collapse and/or separate with age. Fluid-filled "hydraulic" type mounts can often leak, allowing annoying engine vibrations to be transmitted to the chassis.