wintersubaru Posted April 14, 2005 Share Posted April 14, 2005 I have noticed that when i take the breather tube off the right valve cover that a lot off blow by was coming from it when i pulled it to pour some sea foam down it with it running. So my question is what is the cause of this? the left side is fine. The T.O.D. is louder on the right side. thanks for the feed back Link to comment Share on other sites More sharing options...
subyrally Posted April 14, 2005 Share Posted April 14, 2005 when my rx was having blowby issues, it turned out to be a blown piston ring. Link to comment Share on other sites More sharing options...
All_talk Posted April 14, 2005 Share Posted April 14, 2005 Yep, blow-by is due to poorly sealing pistion rings (worn, broken or stuck), and/or baddly worn ring lands. The way the stock PCV system designed, fresh air is draw in at the passenger side valvecover and case vapors are drawn out on the drivers side, but if the PCV valve is stuck or the blow-by is bad enough it will push vapors and oil out both (and a whole lot of other places). Gary Link to comment Share on other sites More sharing options...
wintersubaru Posted April 14, 2005 Author Share Posted April 14, 2005 Yep, blow-by is due to poorly sealing pistion rings (worn, broken or stuck), and/or baddly worn ring lands. The way the stock PCV system designed, fresh air is draw in at the passenger side valvecover and case vapors are drawn out on the drivers side, but if the PCV valve is stuck or the blow-by is bad enough it will push vapors and oil out both (and a whole lot of other places). Gary no oil comming yet so maybe pcv valve i hope. Link to comment Share on other sites More sharing options...
markman34 Posted June 22, 2005 Share Posted June 22, 2005 interesting that there is a flow from one side to the other with the pcv system. I have hooked up a catch can that accepts both pcv nipples off of the valve covers. Is this bad? Do I need to have the one side connected to the air cleaner boot? Does this side (passenger side) provide fresh air to the pcv system? very interesting........ Is there a hazzard to not having the air supply to the pcv system? When does the pcv valve open? Does it fail open? Does it operate on vacume or fluid level? And...... what is a normal amount of pcv gas coming out of the engine. My oil filler cap huffs pretty hard when I take the cap off. So many questions Link to comment Share on other sites More sharing options...
NorthWet Posted June 22, 2005 Share Posted June 22, 2005 Ok, PCV 101: A standard PCV system is designed so that it ventilates the crankcase under both low-load, high-vacuum and high-load, low-vacuum conditions. To handle the low-load, high-vacuum, a hose is connected from the crankcase to the intake manifold "below" the throttleplate using a PCV valve, which is pretty much just a spring-loaded check valve that prevents backfires from igniting your crankcase. For high-load, low-vacuum, the system has a line that runs to the intake system "above" the throttle plate (usually air cleaner housing). Additionally, there is usually a vent line that takes filtered air from inside the air cleaner housing. The PCV valve usually fails due to getting gummed with gunk, so it can fail closed, open, or part way between. The oil filler "huffing" is probably little more than the crankcase "pumping" air as the pistons move. If one valvecover vent is moving air and the other is not, I might check the one that is not and make sure it is not obstructed. They are both connected to the same pressure source (the crankcase). Link to comment Share on other sites More sharing options...
1984subaru Posted June 24, 2005 Share Posted June 24, 2005 I have noticed that when i take the breather tube off the right valve cover that a lot off blow by was coming from it when i pulled it to pour some sea foam down it with it running. So my question is what is the cause of this? the left side is fine. The T.O.D. is louder on the right side. thanks for the feed back BLOW BY ON SUBARU STANDARD Link to comment Share on other sites More sharing options...
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