Has anyone run both the 'clean' and 'dirty' PCV lines into their catch can?

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THarber

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You can't combine clean and dirty side lines, you'll have basically a large vacuum leak then. Clean side air goes into an air metered location forward of the MAF. The dirty side is really all you need to put a catch can on and should be more than enough for any N/A engine. If you go with a blower, then there are other things to consider and both lines might need a separator.
 

davidavidd

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Yeah, I didn't articulate my current situation well. I was thinking ahead. I just replaced a bad head gasket (and I did both head gaskets at the same time)...so I saw tremendous amounts of oil out that 'clean pcv' side into the intake...as that was the side where the head gasket let go. I'm sure it was 'pushing' oil out that side. However, when pulling the engine apart, the driver's side (dirty side) pistons/plugs were also coated with oil, even though the head gasket was intact. I was just thinking of doing some forward-thinking to keep the entire process as clean as possible when I finish this recent engine repair. That way, if something DOES happen to one side of the engine (like a head gasket again), I could limit the damage done by limiting any future oil introduced into the system to keep oil out of the intake and possible keep the healthy side in decent working order.

I did clean/check the PCV valve in the dirty side (with the updated version valve cover I recently purchased) during the prep for the new heads/gaskets, and it seems to be working correctly. I also know that while I did a marginal job cleaning the tops of the pistons, since they were coated pistons, I didn't go too crazy and risk removing the coating. I wanted to break the engine in a bit with the new gaskets then run a little seafoam through to clean off what buildup is left over on that side. I just wasn't sure if the catch can would limit air flow to the point where having both run through the can would be a detriment to the system. Sounds like it isn't...so I will proceed with my modifications.

Thanks for the heads up. I searched the forum for a few minutes. Saw lots of catch can installs, but none specifically calling out connecting to both pcv lines.
Hello, that was me. My engine spit oil on the clean side under a high stress situation. Luckily it didn't happen again, now I have a catch can (open to air) in that hose.
 

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