BMW E65 power tailgate won't open or moves slowly
Why does the E65 power tailgate close or rise slowly?
Usually the hydraulic lifter cylinder is leaking oil and there is too little oil. The motor hums, but the tailgate moves slowly or jerkily, especially in cold weather. If the cylinder leaks from the rear end, it must be replaced.
Where and what oil is added to the tailgate hydraulics?
The pump is in the boot behind the right side trim panel, with a white oil reservoir under it. Use BMW's own or green hydraulic oil, because ordinary ATF stiffens in the cold. Topping up the oil is not always enough, and some parts may need replacing.
Tailgate won't open or close at all - what should be checked?
First check the pump fuse. The fuse box is under the right-hand hatch of the tailgate. The system may be in a fault state, in which case removing and refitting the fuses may get the tailgate working. Replacing the gas struts alone does not fix a cold-weather fault.