Originally Posted by
skyblue
Cheers.
Can anyone explain, when blow by occurs what prevents the blow by from exiting through the breather hose?
In my head I imagine that some of it goes out through the PCV valve (and therefore cannot return) and some goes up the breather hose. During the exhaust stroke the blow by that snuck up the breather hose gets pulled back into the crankcase by the vacuum and the fact that it can't come in through the PCV valve. This process ensures the blow by never sneaks out of the breather meaning the gas never comes out in front of the butterfly and map?
However when the blow by gas is trapped on the outside of the PCV valve it's sitting in the intake (on the engine side of the butterfly and map), which would push the air already there out a bit, would this likely contaminate the MAP sensor over time considering it's on the engine side of the butterfly valve?
Am I on the right track?
I wonder how much blow by gas gets pushed into the intake space and how far back it goes toward the throttle body or if it even gets close.