Why your Air Oil Separator doesn't work

There is a bit of a debate in the Subaru community about putting on a Catch-Can Vs. an Air Oil Separator.  The AOS wins out most of the time, and for many people, it works well.

But sometimes the AOS can run into some interesting issues, especially as cars make more power or go on track with sticky tires.

So is the issue with the Specific build?  A particular AOS?  Or is the issue something deeper?

We have been working to find a better understanding of what is going on with the Subaru PCV system for a while now, and it seems like it is time to have a conversation about about Air Oil Separators, and why they aren't exactly the solution that we all thought they were.

Thanks for watching and Stay Tuned!

Here are some links to related videos if you want to find out more about some of the topics discussed in this video:

An In depth look at what Crankcase Pressure can tell us on a Turbo Subaru Engine

How can you tell if your PCV System is working?

How and why we changed our Dry Sump plumbing

Taking a look at the Subaru EJ25 Turbo PCV System

Is an Air Oil Separator just a Band-aid?

A look at Air Oil Separator Configuration - Recirculating Vs. Atmospheric