PCV Question

[Dr_Snooz]

I'm noticing that my PCV system is something of a mess. The breather box is leaking oil from the block (not the lower hose). The upper hose is brittle and cracking. When I pull the rubbish replacement engine I just put in for the warranty replacement I'll be getting :banghead: , I'm probably going to replace everything with new parts. Before I do though, I'm curious about the little air cleaner elements a lot of you have dangling from your valve covers where the PCV system would normally connect.
Can anyone give me pointers on how that works? Do you remove the breather box and plug the block? If so, how? Or do you just plug the breather box? Do you pass California smog like that? I did a search but couldn't find anything really germane.

Thanks!

[turabaka]

you mean a breather filter? I replaced mine when the pcv filter on the stock airbox was all gunked up. It doesn't really do much, just keeps dirt from getting into the valve cover.

[Dr_Snooz]

you mean a breather filter? I replaced mine when the pcv filter on the stock airbox was all gunked up. It doesn't really do much, just keeps dirt from getting into the valve cover.

Yeah. What did you do about your breather box on the back of the block?

[turabaka]

On the back of the block? perhaps I could get a picture? if you're talking about what I think you're talking about then you'll probably have to get that fixed. I was talking about the pipe that comes off of the valve cover and has the hose attached to it that goes to the air filter.

[Dr_Snooz]

Oops. Sorry. I've got fuel injection which is routed a little differently. Per below, the PCV system goes from the back of the oil pan, up the hose (#3) to the breather box (#1) through the #5 neck to the purge control valve (#18) and back into the valve cover. Pretty much all of that needs help on my car. I'm just wondering how others are dealing with it. I'm going to replace everything, but it looks like some people are getting more creative.

http://www.hondaautomotiveparts.com/auto/jsp/mws/prddisplay.jsp?inputstate=5&catcgry1=Accord&catcgry2=1989&catcgry3=2DR+LXI&catcgry4=KL4AT&catcgry5=BREATHER+PIPE-OIL+FILTER

[turabaka]

hmmm. It looks to be like you're going to have to replace the whole thing. Maybe some of the more experienced guys can jump with their two cents. I'd be interested to know what they did.

[Demon1024]

The breather on the valve cover keeps dirt out, but really it's because (in my case) the line returns crank gas to the intake and my new intake doesn't have that connector,.but it also means more clean air going to the engine = more power not much but yeah....
You need you pcv system. just replace the hoses and what else you find.

[DBMaster]

I'll bet that it is the hose connecting the oil pan to the bottom of the breather box. Mine is as hard as a metal line. I replaced the grommet and line from the box to the bracket that holds the PCV. It's not easy to access or replace.

[cygnus x-1]

The little breather filter on the valve cover is mostly just to keep junk out of the system. Air is pulled in through that breather, goes down to the crank case, then into the oil separator box on the back of the block, up through the PCV valve and into the intake manifold. The idea is to circulate fresh air through the crank case to remove blow by gases that eventually would lead to sludge and moisture buildup. Normally the valve cover is vented to the main air cleaner box so it can get fresh filtered air from there, so pretty much the same thing.

You really do want the PCV system working properly so if it's leaking you pretty much just have to replace the old hoses. The breather on the valve cover really does nothing except maybe make the engine look slightly less cluttered. PCV systems do tend to gunk up the intake though since all the gases and oil vapor go back into the engine to be burned with the air/fuel mixture. You can lessen this by adding a catch can between the PCV valve and manifold vacuum port. The can traps some of the oil so that it doesn't go back into the intake. Do a google search for "pcv catch can" and you'll get tons of info. I tried it and was surprised how much oil goes back into the intake.

C|

[DBMaster]

I tried it and was surprised how much oil goes back into the intake.

Especially true since these are old engines. You get a lot more blowby than when new.