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How to diagnose and repair a Volkswagen or Audi 2.0T / 1.8T failed PCV valve

One of the most common failures on the turbocharged VW and Audi 2.0T and 1.8T engines is the PCV valve diaphragm. The most common mode of failure is the diaphragm tearing. 

Luckily RKX has a solution! We have created an upgraded PCV valve that is nearly indestructible. This PCV valve is precision made in Germany and uses a fabric mesh reinforcement. 

The positive crankcase ventilation valves (PCV valve for short) job is to regulate how much vacuum is on the crankcase of the engine to regulate the crank case vapors. It does this by the PCV valve diaphragm. The PCV valves job is to regulate the PCV flow through the engine based on vacuum. At idle the engine has high vacuum, this vacuum will pull down on the PCV valve partially sealing off the crankcase to reduce vacuum on it. Under acceleration when there is more crank case pressure and less engine vacuum the PCV valve will be wide open to allow for more PCV flow. 

When the PCV diaphragm gets a hole in it, it will essentially cause an increase of vacuum on the crankcase especially at idle as the car will not be able to "suck down" the PCV valve to reduce flow. The main symptoms of a torn PCV valve are:

  • Increased vacuum on the crankcase especially at idle
  • Rough Idle
  • Check engine light on typically with codes for running to lean
  • Hissing sound coming from the PCV valve cap breather

By far the easiest way to diagnose a torn PCV valve is to check for vacuum present at the PCV valve cap breather port. If you can feel and hear vacuum coming from it this is 100% an indication that there is an issue with the valve. When working properly this vent is simply there to allow the diaphragm to move up and down without trapping air behind it. When the valve tears it creates a passageway for the vacuum on the engine crankcase to escape through the breather. 

Replacing your PCV valve with an RKX upgraded PCV valve is super simple. Just unclip the 6 locking tabs on the cap, remove the old diaphragm and spring guide, clean the sealing surfaces, reinstall the new upgraded PCV diaphragm with spring guide making sure the valve is centered in the cap and then simply snap down the new cap making sure all 6 locking tabs snap into place. 

We always recommended reusing your old PCV valve spring whenever possible. While this kit fits tons of applications as all the diaphragms are identical, each application may have a slightly different spring rate. The spring is what regulates the flow of the PCV when it is working properly and using the wrong spring could cause minor issues. The spring rarely if ever fails so there is no reliability advantage to replacing it unless you have to. 


You can find the RKX Upgraded PCV valve Here


 RKX also has many other upgraded PCV valve repair kits available here

Compatible with these PCV assemblies and more: 06H103495A, 06H 103 495A, 06H103495B, 06H 103 495B, 06H103495AK, 06H 103 495AK, 06H103495AE, 06H 103 495AE, 06H103495AC, 06H 103 495AC, oil separator assembly, 06K103495AG, 06K 103 495AG, 06K103495AT, 06K 103 495AT, 06K103495AG, 06K 103 495AG 06K103495R , 06K103495J

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