Re: AOS/CC discussion about air oil separators and catch can
Posted: Tue Aug 24, 2021 8:28 pm
So the first step is with a stock/ish car, use inlet pressure testing to verify there’s no leaks in the pcv system.
At some point you may need soap or bubbles, brake cleaner or unlit propane: see the inlet pressure testing diy post.
You’ll also want to replace, fix or more likely upgrade the following parts which are known failure points that will ultimately affect your fuel trims with negative results.
Stock tmic: upgrade or recrimp
Inlet pipe: silicone, eg psr v2, Perrin.
Throttlebody hose: essential, Kobe or AVO etc.
Pcv valve: check clean or replace.
Pcv hoses: oem is good for packaging, not forever durable… I reinforce the ends with glue heat shrink to protect the ends.
Upper and lower inlet manifold gaskets & orings.
Injector seat seals.
The stock system is ok for stockish boost, not because it holds any pressure, but because of stock blow by with a healthy engine.
As such you want check and especially clean out however much oil is present in your inlet tract over how many km.
You then repeat the test at a later date to see if it’s minimal, still a few drops of oil, or if you have an issue requiring mitigation.
At some point you may need soap or bubbles, brake cleaner or unlit propane: see the inlet pressure testing diy post.
You’ll also want to replace, fix or more likely upgrade the following parts which are known failure points that will ultimately affect your fuel trims with negative results.
Stock tmic: upgrade or recrimp
Inlet pipe: silicone, eg psr v2, Perrin.
Throttlebody hose: essential, Kobe or AVO etc.
Pcv valve: check clean or replace.
Pcv hoses: oem is good for packaging, not forever durable… I reinforce the ends with glue heat shrink to protect the ends.
Upper and lower inlet manifold gaskets & orings.
Injector seat seals.
The stock system is ok for stockish boost, not because it holds any pressure, but because of stock blow by with a healthy engine.
As such you want check and especially clean out however much oil is present in your inlet tract over how many km.
You then repeat the test at a later date to see if it’s minimal, still a few drops of oil, or if you have an issue requiring mitigation.