If the e39 OEM CCV is changed with a 39M5 cyclone separator (which has no diaphragm), and at the bottom we fit a check valve so as to avoid oil suction, would that not be a better solution? The M5 cyclonic separator has the 2 main lines going in/out and the bottom for the oil separation, pretty much like the OEM diaphragm CCV. But now, you eliminate the freezing of the diaphragm, or the rupture of it. Not sure if the vacuum is at the correct spec, but this will allow to keep the hoses where they were in a OEM built car, so you still have access to everything else pretty easy.
Looking for a DIY? Parts? Check this out, it might be your ticket
TMS underdrive pullies - Stewart WP - PSS9 - Beisan Vanos seals - Zimmerman cross-drilled & Akebono Euro - Deka 649 MF - 55w HID headlights - 35w HID foglights - Hualigan double din - ACS (rep) alu pedals - Euro central storage console - Breyton Magic Racing staggered wheels - M5 bumper - M5 steering wheel - Tint
Stable: e39 M54, e53 N62 & Tribby