Lack of vacuum at idle and during low engine load conditions is something that is to be expected with any kit that removes the connection between the intake manifold and the PCV valve or crankcase. At this time, we are not aware of any catch can kit for this chassis/motor that retains the connection between the manifold and the crankcase. Without the intake manifold connected to the system, the only vacuum that will be available will be the light vacuum that is created by the turbo. This should never be present at idle, so it is reasonable to expect there to be a small amount of crankcase pressure at idle.



Before beginning the design of this catch can kit, we spent a lot of time analyzing and understanding the TSI PCV system. During this analysis, it became very clear that the oil separators in the OEM PCV system were a product of lots of R&D at VW/Audi, so we felt that supplementing them would be a better option than removing them entirely. This approach results in superior system functionality with less maintenance, while allowing us to pass the cost savings on to the customer by not having to replace the PCV valve with an expensive to machine billet part.



Through our analysis of the system, we determined that by capping off the connection between the manifold and the PCV valve, we would be able to eliminate the failure-prone check valve, while maintaining the OEM “charging mode” flow path under all conditions – (idle, low load and full boost). With any PCV system, blow-by and resultant crank case pressure are at their greatest when under high load (high boost)/high RPM operating conditions, making this an ideal way to use both the OEM oil separators and our baffled catch can.



At this time, it is unclear if the reported issues with leaking seals are related to the piston ring sealing issues in early B8s, failing PCV valves, or a combination of both factors. All of our testing was completed with the most up to date PCV valve available at the time. With that in mind, it is necessary to have a fully functioning PCV system before installing this kit to ensure proper functionality. During initial testing, we logged crankcase pressure with and without the intake to PCV hose installed. The results of the testing were very favorable, and the kit has remained installed on our shop B8 since prototype testing began with no signs of oil leaks.



Through our recent research, it appears that the issue with leaking seals seems to be exclusive to early vehicles. We are continuing to look into this matter, and would be happy to swap an updated PCV valve for a customer with our kit installed who is experiencing leaks at the turbo seals to confirm that a faulty valve can cause the conditions seen by some forum members. Please PM for more details if you meet these testing criteria.



Thanks!