Tdi Cyclonic Crank Case Breather
The cyclonic breather uses centrifugal air-flow to separate air and oil from crankcase emissions. A failed unit can leak oil onto the top of your engine, or worse yet allow large amounts of oil charged air into your intake pre-turbocharger, leading to wetting out of the intercooler, smoke, and potentially a runaway engine fueled by heated engine oil.
The plastic units (genuine and aftermarket) are all sonic welded and have an average lifespan of 5+/- years of regular use. Extreme use, or long periods of inactivity can lead to failure prior to the average lifespan. For a more forgiving solution consider the Allisport all Aluminum Upgraded Version available
Regardless of the the unit installed, service is recommended to ensure proper function. Clean out the interior of the cyclonic breather every year to ensure no solidified blockages are present.