DTN

^^ I've found my internal oil catch clogged twice now. Whenever my car starts acting funny, i find oil in my intake. Whenever I catch a nitrous backfire ( i believe) my internal catch can clogs. I posted a DIY on how to clean the internal catch. It works. Then I backfire and the internal catch cloggs with burnt fuel/oil mixture from the nitrous/fuel entering the breather..

I'm thinking about drilling a small, 1/4" hole above the stock internal oil catch and having a small removable plug, so that I can clean it with a pipe cleaner whenever it clogs. There is no way you should need a catch can, or a new PCV every few months if the drain is working correctly.

radu_rd2

Still, leaving the PCV line as is stock is still a problem when turboing: you're spilling boost into the crankcase through the PCV and spewing shit out the breather..

tanc

There is a check valve on the PCV which does not let positive pressure in the PCV, you can boost 1000psi and you won't get any in the crank case if you have the pcv set up like stock.

DTN

^^ yeah, but you put it into the breather. Breather should be routed before turbo or to open air.

Otherwise you're pressurizing your engine and that increases time to build up boost on your intake piping.

radu_rd2

^^ tanc: Read my post on the previous page. The PCV valve doesn't do that, why would it? The N/A engine has no positive pressure in the manifold. The PCV valve actually does the opposite thing, limit the flow OUT of the crankcase when there is too much vacuum in the IM (at idle). Don't believe me? Unplug the PCV line while an NA engine is idleing, and you'll see it die.

Another quote from Yahoo Autos: The PCV valve is a spring-loaded valve with a specific orifice size designed to restrict the amount of air that’s siphoned from the crankcase into the intake manifold. This is necessary because air drawn through the valve from the crankcase has a leaning effect on the fuel mixture much the same as a vacuum leak. So air flow through the valve must be controlled within certain limits. At idle, air flow is reduced because little blowby is produced. When the engine is cruising and vacuum is high, airflow through the PCV valve is at a maximum to purge the blowby vapors from the crankcase.

DTN

^^ if I remember correctly, there is a dual action to the PCV valve. it reduces flow one way, opens flow in the middle and cuts off flow the other way. There's 2 springs.

radu_rd2

I'm not sure, but why would they bother? It makes no sense for a NA engine to limit the flow in the other direction.. I read about it in a couple of places and none of them mentioned that it has two springs or that it also limits the flow if there is pressure in the IM.. E.g. look at the picture on this page: http://autorepair.about.com/cs/gener.../bldef_621.htm

Well, there's one way to find out.. I could take the valve out and try blowing air through it, maybe with a pump smile.gif But at this point I'm 99% sure I'm right, otherwise why would turbo people complain about oil spewing out the breather??

JonGTR

Radu, look, we read your post! We know what a PCV valve does. It's ONE WAY. That means it will allow air to be pulled into the intake manifold, but not allow boost into the crank case.
If you don't believe us, then take yours off and check it yourself. Or replace it because it's broken.

We're done arguing about how a PCV valve works.

radu_rd2

I am a noob, and I am trying to learn first of all. I know you guys are very knowledgeable, but I will not accept this as it does not make sense to me. I will not accept that Hyundai installed a component that would keep boost out of the crankcase of a NA engine.

Here is a PCV valve that works for boosted vehicles. It's two way, and it does both what I say a regular PCV does, and what you say it does. And it has a boost limit (30psi), as should be normal with any piece of hardare:
http://fasthyundai.com/shop/item.php?i=RIP_PCV001

Looks a bit different doesn't it?

AND As i mentioned, I tried disconnecting the PCV hose while the engine was running and guess what? It died! You try it if you don't believe me. How does your explanation of the PCV valve explain this ?

tanc

Radu my friend, you need stop googling PCV valves and take your valve cover off and look for yourself.

AIR CAN NOT ENTER YOUR CRANK CASE FROM YOUR INTAKE PIPE. Go blow into your pcv valve and let me know how that works out for you.