It's fine to drive, just don't keep it as a daily driver while this is malfunctioning as it'll waist oil, foul plugs and cats w/ continual driving. I don't know if they'll want to remove the intake manifold to replace the seperator because it's not necessarily needed, but it's much easier w/ the manifold off...in exchange for more work since they move the intake.
Have you considered just replacing it yourself? I have a pre-VANOS intake manifold sitting in my garage, I can take pics if you need to give you some guidance on how to remove this item yourself. I'm sure there are also some write-ups on
www.e38.org, but if you'd like actual realtime help, I can assist you.
__________________
650hp 10 X5///M - Stage 2, Vibrant 1794's , gutted cats, custom intake, AC Forged 22's
325hp 98 BMW 740iL -
///M5 6spd,
www.bavengine.com w/ Performance Option, electric fan, CF intake tube w/ heatshield, Mag 14816 w/ notched bumper, Bilstein/H&R Stage II/Powerflex
600+hp 02 Harley F150 - MHP900 Stage 3 engine, KB2.3, 8# lower, 60# inj, Walbro FP's
135hp 01 TL1000R - M4 full exhaust, K&N, Yosh box, -1/+2 gears, 2CT's