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Discussion Starter · #1 ·
So I followed the lead of many members and pulled the hose from the crankcase vent off the intake box. Cut the hose down to about 6-8 inches and put the small breather/filter on it and forgot about it. The other day there was a strange sound of air pressure release. When I opened the hood, there was quite a bit of oil around the breather/filter. I'm guessing it got plugged and the sound I heard was the vapors forcing their way out.
My question is this: what alternative is there to reconnecting the hose to the intake box? It seems like the ideal place for a catch can (what I know about engines is what I've learned from reading in the forum). I don't want that sludge going back into the intake. Can the crankcase vent hose be routed down through the engine bay and just emptied to the road beneath me? I realize it's not the most environmentally clean idea.:i_rolleyes:
 

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So I followed the lead of many members and pulled the hose from the crankcase vent off the intake box. Cut the hose down to about 6-8 inches and put the small breather/filter on it and forgot about it. The other day there was a strange sound of air pressure release. When I opened the hood, there was quite a bit of oil around the breather/filter. I'm guessing it got plugged and the sound I heard was the vapors forcing their way out.
My question is this: what alternative is there to reconnecting the hose to the intake box? It seems like the ideal place for a catch can (what I know about engines is what I've learned from reading in the forum). I don't want that sludge going back into the intake. Can the crankcase vent hose be routed down through the engine bay and just emptied to the road beneath me? I realize it's not the most environmentally clean idea.
A catch can will best fit what you're looking for. The system uses the vacuum from the intake to "suck" the blow-by out of the crankcase. With just a breather it allows the fumes to sit in the crankcase longer and build up before getting pushed out from the pressure. If buying a catch can is what's holding you up, watch a YouTube video on how to make your own. And if you make one please post pictures!
 

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That's not a good idea to set it up the way you did, you want engine vacuum to evacuate those fumes. Install a catch can if anything.
 

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Discussion Starter · #4 ·
A catch can will best fit what you're looking for. The system uses the vacuum from the intake to "suck" the blow-by out of the crankcase. With just a breather it allows the fumes to sit in the crankcase longer and build up before getting pushed out from the pressure. If buying a catch can is what's holding you up, watch a YouTube video on how to make your own. And if you make one please post pictures!
Thanks for replying Eddie. My only concern is that if I install a catch can on the crankcase vent hose, there won't be the vacuum needed like if it went to the intake box. So if I did the cc, what creates the suction to pull the blow-by out?
 

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Discussion Starter · #5 ·
BTW-I have a catch can that was installed in the pcv hose that wasn't collecting anything, even after a few thousand miles. And I know it was installed correctly.
 

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A catch can will best fit what you're looking for. The system uses the vacuum from the intake to "suck" the blow-by out of the crankcase. With just a breather it allows the fumes to sit in the crankcase longer and build up before getting pushed out from the pressure. If buying a catch can is what's holding you up, watch a YouTube video on how to make your own. And if you make one please post pictures!
Thanks for replying Eddie. My only concern is that if I install a catch can on the crankcase vent hose, there won't be the vacuum needed like if it went to the intake box. So if I did the cc, what creates the suction to pull the blow-by out?
The catch can has 2 ends to it. One end goes to the crankcase breather port and the other end to the port in the intake where the tube went originally. The larger area of the can allows the heavier oil to drop to the bottom and collect while the clean air travels out the other port and into the intake. I pulled a picture off google where you can see one end coming out of the breather and the other end going into the intake.
 

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Discussion Starter · #7 ·
Thanks again Eddie. My confusion was from the idea that catch cans were only meant to be used on PCV hoses and not the crankcase vent. I don't think I've ever seen a cc installed on the crankcase vent hose. It definitely makes more sense now.
 

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They are meant to be used on the PCV hoses, not the crankcase vent. I guess you could add one there, but a bigger question is why do you have so much crankcase pressure?
You don't want an open breather hose, you want it after the air filter or add an extra filter - you don't want to be sucking dirty air into the crankcase.



I would guess you either have a PCV problem or a serious blowby issue - unless you are supercharged.
 

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They are meant to be used on the PCV hoses, not the crankcase vent. I guess you could add one there, but a bigger question is why do you have so much crankcase pressure?
You don't want an open breather hose, you want it after the air filter or add an extra filter - you don't want to be sucking dirty air into the crankcase.



I would guess you either have a PCV problem or a serious blowby issue - unless you are supercharged.
The pcv system is the crankcase vent in most cases. And the crankcase does not suck air in. It blows it out.
 

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Am I missing something? PCV is Positive Crankcase Ventilation-it is a crankcase vent
 

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There are 2 sides to a PCV system, the PCV valve side and the fresh air side.
PCV side goes from (usually) a valve cover to intake manifold through the PCV valve AND fresh air is supplied from the air cleaner to the valve cover (in most instances).


The reason is you do not want a negative or a positive pressure in the crankcase ,as it is hard on seals. So at part throttle the PCV valve flows the most and less at idle .
Since the fresh air side is connected to the air cleaner after the filter any excess pressure is vented through it and sucked through the throttle body.


Since he doesn't seem to have any in his catch can and an abnormal amount in the breather hose end (fresh air side), I would suspect either his PCV valve is not working or there is a problem with his catch can install, such as using a cheap hose that is collapsing under vac..
 
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