Crankcase Vent Valve / Oil Separator - E90 325/330 E60 525/530 Z4 3.0i/si

This is an aftermarket E90, E60, Z4 Oil Separator made by Febi-Bilstein and comes with a two year warranty. The crankcase vent hoses are strongly recommended as they tend to break when removed.

The early E90 N52 crankcase vent system (CCV) has an external oil separator and hoses. The oil separator is bolted to the underside of the intake manifold with a hose coming from the valve cover, one going to the intake manifold, and a drain hose going to the dipstick tube. The oil separator and two of the hoses are insulated and heated to prevent sludge from building up inside the system. However, if the system is not working as intended too much oil in the intake air will lower the effective fuel octane, lead to drivability issues, and cause increased emissions. A completely blocked E90 CCV has the potential for very serious engine failure (hydrolock) if liquid oil ends up in the intake. Signs of a failing CCV include: whistling noises in the intake, blueish smoke in the exhaust, high oil consumption, and thick white or yellow gunk under the oil cap.

Replacing the oil separator on the E90 N52 requires removing the intake manifold so new manifold gaskets are also required.