Have you checked the vacuum is working correctly? The vacuum is controlled by a small pressure converter, similar to the unit that controls the turbo boost.

From the manual: -

Actuation of controlled damping mounts
In the basic setting, there is no vacuum at the control component od the mount. The bypass in the mount is closed. Hydraulic fluid flows back and forth through a ring channel between the upper and lower chambers in the mount. The mount acts like a conventional hydraulic bearing. The mount has hard damping.

If a vacuum is applied to the mount's control component, the bypass will open. The hydraulic fluid then flows back and forth between the chambers through a larger cross-sectional area. The mount has softer damping.

Engine mount control
The controllable engine mounts are switched to ”hard” or ”soft” corresponding to operating conditions.

Function
The pressure converter connects the engine mounts to the vacuum supply. When activated by the DDE master control unit, the pressure converter switches vacuum to the engine mounts which in turn switch to ”soft”.
The engine mounts are activated at:
- low speeds (under around 60 km/h) and
- below engine speeds that are dependent on the coolant temperature (the engine speeds are between 1000 rpm and 1200 rpm)

Troubleshooting
If a defect occurs in the activation of the pressure converter, a fault is stored.
The engine mount control is switched off if one of the following faults occurs:
- ”Driving speed signal”
- ”Coolant-temperature sensor”

You might need a small hand-held vacuum pump to set/check the mounts operation, as well as getting a reading from the output of the pressure. converter.

__________________
Wayne
2005 BMW X5 3.0d (b 02/05)
2001 BMW F650GS Dakar (b 06/01)