I've got a 9/99 production with 114K miles and it seems to get the rattle every time I start it now, even after being shutdown for an hour or so. In the past it would do this but only after half to one day or more. It seems like the Vanos accumulator isn't doing it's job. The rattle goes away after a few seconds but is irritating. Before throwing parts at it, is there any way to test the unit for leakdown? I haven't found any leaks in the various hoses and the Vanos solenoid o-rings are only two years old. Could there be a leak internal to the Vanos units?