So I just just picked up a 2021 AT4 and was researching catch cans. Wondering why install a catch can that only is catching oil from the drivers side valve cover. Isn't all the oil vapor from the passenger side still venting into the air box and ending up in the intake track / valves?
Catch Can. Why only one valve cover?
- Thread starter jasonp
- Start date
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Antonm
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Because air goes into the valve cover (the passenger side one) from a tube connected to the air intake (filtered air), and air/ oil vapor mix is drawn out of the engine through the other valve cover (the driver side one), then routed back into the intake behind the throttle body to be burned.
So putting a catch can on the passenger side valve cover would be totally useless as the air is going into the engine, not out, on that side.
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So putting a catch can on the passenger side valve cover would be totally useless as the air is going into the engine, not out, on that side.
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BlaineBug
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I have a catch can routed on my rig but I'm still confused about the route of flow. Looks like both valve covers connect to the air intake tube pre-throttle body. Those connections are left unaltered and connected in place. But then you have the catch can routed in-line in-between another line that connects the intake manifold to the engine block I am assuming. Still a bit confused.
Antonm
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What year and what engine? Also could you post some pictures of this, sounds completely different from mine and all the ones I've seen. I'd be interested in seeing this setup.
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BlaineBug
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2019 prior-gen body style with 5.3. There's the PCV valve below the throttle body and then the suction is from the intake manifold. You plumb these lines to the catch can, not the lines on top of the valve covers.
enginehead
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isn't it a good idea of have the oil going onto the valve? how else do they get lubricated? there are valve stem seals on the tops of them. is it just me or doesn't that seem like the factory did that breather set up for a reason?
Marky Dissod
Full Access Member
Positive CrankCase Ventilation / breather setup has NOTHING to do with lubricating valve stems / valve seals.
