Air / Oil Separator...
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Air / Oil Separator (or Oil Catch Can) install.

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This was done on a 1zz way back when, same procedure for the 2zz tho.

Reason: Sometimes gases will slip past the piston rings and will increase the pressure in your crank case. When this happens your crank case needs to ventilate this pressure, this process is done through the PCV valve (check valve). Since it is against nature to vent these gases into the atmosphere, car manufactures plumb a line from the crankcase back into the intake for the engine to eat/recycle. The issue with this is the vented gases from the crankcase will usually contain trace amounts of oil vapors, condensation, gas etc. which "may" gunk up your TB, Intake Manifold, Valves, and maybe some sensors along the way. By installing an Air / Oil Separator or Oil Catch Can you can remove some of these containments from re-entering your engine through the intake side.


Note: In super super heavy racing scenarios you may want to include a return line back to the oil pan but I wont go into it here. Realistically if you are racing so hard that you need a return line back to the oil pan you will not be reading this diy anyhow.


Here I am using an Oil / Air Separator. It differs from an Oil Catch Can because there is actual filter media (OCC better for FI since no reduction in flow from filter. Blow-by much greater in FI). There is a reduction in flow for the vented gases however since this a NA stock 1zz nothing to really worry about. Even a tuned 1/h/e 2zz I still think this setup is fine, it really depends how much gas is getting by your rings. 




Heres my setup


Hose at the bottom is coming from the PCV valve which routes into the Air / Oil Separator which then goes to the intake nipple.


Here is the oil that would have gone back into my intake. 




Air / Oil Separator from JEGS. The filter media can be purchased separately which makes servicing it much easier. They are fairly cheap.


Should last between 1500 - 2000 miles before needing to be empty, although this is dependent on how "tired" your engine is.

Posted : October 11, 2019 10:07 pm