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Performance Parts for Euro, JDM & American Autos.

Product Image WEISTEC M156/M159 Oil / Air Separator

WEISTEC M156/M159 Oil / Air Separator


Weistec's Oil / Air Separator system is a must have for completely stock vehicles, to those upgraded with the Weistec Supercharger. The separator system vastly decreases oil retention by the engine, reduces detonation (Knock), and can ultimately save the life of the engine internals.

As the excess crankcase pressure is vented through the PCV valve and into the intake manifold the engine will eventually draw in, not only air which is wanted, but also particles of aerated oil which creates instability in power due to the low octane level of oil.

Key Features:

  • Eliminates the anti octane properties of oil
  • CNC machined 6061 aluminum
  • Hard anodized to military spec
  • Direct bolt in for M156/M159 vehicles
  • Utilizes brass filter elements
  • 100% serviceable
  • Flexible and reversible mounting and installation


Pictured below are typical intake manifolds from both M156 and M159 engines after 8-15,000 miles. It is very clear the amount of oil that is being drawn in by the engine.

The Weistec Oil/Air Separator System comes equipped with billet PCV adapter fittings for easy bolt on performance, and accumulates oil in the lower body which can be drained and recycled during every oil change*

*Some vehicles may have more oil consumption or "blow-by" than others. If you are unsure whether your vehicle may or may not be one of these, check the oil separator every 3,000miles (5,000Km) to ensure the separator system is not filled.

Supported Platforms
  • 2008-Present C63 AMG (Sedan and Wagon)
  • 2012-Present C63 AMG Black Series
  • 2007-2008 CLK63 AMG
  • 2008 CLK63 Black Series
  • 2007-2010 CLS63 AMG
  • 2007-2011 E63 AMG (Sedan and Wagon)
  • 2007-2010 S63 AMG
  • 2007-2011 ML63 AMG
  • 2007 R63 AMG
  • 2008-2010 CL63 AMG
  • 2009-2011 SL63 AMG
  • 2010-Present SLS AMG (Gullwing and Roadster)