5.7 Hemi Poops where it eats? brown stains on air filter? any one else?

p8ntballa9362

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so we're all aware of EGR valves and PCV recirculation crap through out engines for emissions, but after installing a catch can i got to wondering. the crank case vent tube that runs from the intake to the oil cap, is that sucking clean filtered air into the oil cap, then through the crank case, out the PCV into the catch can and then back into the throttle body or is that air flowing out the filler cap and into the air box to be recirculated? if it isnt the latter then why is there a big oily doodoo stain on my air filter? is it off gassing after ive turned the truck off? does it need vacuum to draw fresh air in, or is it passive? wondering about throwing a breather filter on there. but after plugging a hole in the catch can and stalling the motor, theres some serious vacuum going on with these HEMI's and i dont want to fool with that. any advice is greatly appreciated.
 

Dodge 1500 4X4

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Newer ram don't have a EGR valve, and catch cans are getting all the crap out of the PVC going to the throttle body.
 

pacofortacos

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Could be vapors after shutting off, but could also be a PCV valve not flowing correctly or excessive blow by.
It needs a vac. to suck clean air into the engine through that hose.
 

Wild one

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so we're all aware of EGR valves and PCV recirculation crap through out engines for emissions, but after installing a catch can i got to wondering. the crank case vent tube that runs from the intake to the oil cap, is that sucking clean filtered air into the oil cap, then through the crank case, out the PCV into the catch can and then back into the throttle body or is that air flowing out the filler cap and into the air box to be recirculated? if it isnt the latter then why is there a big oily doodoo stain on my air filter? is it off gassing after ive turned the truck off? does it need vacuum to draw fresh air in, or is it passive? wondering about throwing a breather filter on there. but after plugging a hole in the catch can and stalling the motor, theres some serious vacuum going on with these HEMI's and i dont want to fool with that. any advice is greatly appreciated.
The PCV is most efficient at high vaccum loads,like steady state cruising on flat ground,or going downhill etc. If you drive hard, the pcv's efficienty drops as the valve closes under low vaccumn situations ,like you get with your foot close to the floor. Under those circumstances you can get a back feed through the fresh/make up air hose,that can make your filter a bit oily on the top side of the filter. I'm gonna take a guess,you like to feel them 395 horses working,lol
 
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