I think I found my oil leak, and may have it narrowed down to what the service manual refers to as the "oil breather chamber". I pryed (tight fitting bastard) the one from my spare engine and see that it has a o-ring seal.

Should I replace the whole box, or just the o-ring?

Has anyone else had leaks here, and can it be replaced/repaired with the motor in the car? It looks tight, but do-able if I remove the intake manifold bracket.

What does this "oil breather chamber" do, and do I even need it?

Thanks in advance

Pictures from spare motor.

 

Pull it off and look carefully at it. Mine was cracked. Took us quite a while to track it down. We thought it was the O-ring for the longest time.

Warren

 

John, help me out. What part of the motor is this that you're looking at? Looks like the oil filter fitting to the immediate left, is that correct? Is your motor anything like a B series motor?

That's an area of my motor that I don't know real well since it's covered up by the intake manifold. Assuming a B-series motor has the same stuff, this is probably one of the things I whacked my knuckles against whendoing the oil cooler.

 

Its an oil separator box. It sits on the back of the block, the top of it leads ot the PCV valve, which sits in the Inake Manifold at the base (at least on a B-series).

Its like a vent with a catch can. I've always wondered why additional catch cans were needed... i'm sure they're needed, but i'm just not sure why the stocker doesnt work so well.

 

John... clean it up and check for cracks if you dont have any just replace the o-ring and install a new pcv valve also and your leak should go away

by the way hows it going? long time no talk to

 

its just a baffled box to keep the oil in the oil pan, but it cant separate the hot oil vapor, which ends up in the intake manifold. oil doesnt help the engines performance. so that why you need a catch can, to redirect that dirty air out of the intake.

i also recently took a look at the separator chamber, it seems that the oil oring is a pretty weak seal to the engine block. i would definately replace that oring and see if it helps, and maybe find an oversized oring. also, of course check for leaks. i think the soft gasket that surrounds it helps to soak up any leak, and seems like something worth keeping on it next time, even tho its grungy.

 

My understanding is that there things don't really physically hold oil, they just act as a seperating chamber where the oil can fall out of the oily crankcase air. There shouldn't be standing oil up next to the seal, just the oily air being chuffed out by crankcase pressure, especially if you have much if any blow-bye from your piston rings.

I'd say just clean it out (I've not seen a cracked one) and replace the PCV and the O-ring to the bock. On the CRXs, they are covered in a foamy rubber that I always figured was sound deadening but the foam gets oil soaked and nasty so I just strip it off to the bare metal.

 

Yes Karl, sorta just above the oil filter.

It seems to be leaking enough to coat the underside of the car, suspension and transmission with a light coating of oil. After thinking more, here's what I've done:

I've taken the vacume line from the intake manifold that normally connects to the top portion of the PCV, and plugged it. I've ran another hose from to top of the PCV and ran it directly to a catch bottle. I did this because I think I was sucking oil directly into the intake causing the motor to fart heavy oil smoke while cornering.

If I take vacume away from the oil breather box, would it be more inclined to leak?

Lennie, things are well. I didn't know you were on here.

Hard to read, sorry: "This used to connect to the PCV, but is currently plugged"

 

Hehe..I chased the same leak for like 6 months before realizing the actual breather chamber was cracked. replaced the o-ring like 4 times. I'd buy a new chamber.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by johng &raquo;</TD></TR><TR><TD CLASS="quote">
It seems to be leaking enough to coat the underside of the car, suspension and transmission with a light coating of oil...
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John... keep me posted on what you find. My new motor is leaking quite a bit around this same general area, enough to cause drips of of the pan, exhaust, and steering rack! No wonder I was smoking so much in the last PIR race...

I dont know about your motor, but that box is a bitch to get at on my car...

Greg

 

I pick up a new breather box from Honda tomorrow. I'll cram it in this week and let you know.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by johng &raquo;</TD></TR><TR><TD CLASS="quote">I pick up a new breather box from Honda tomorrow. I'll cram it in this week and let you know.
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Let me know if and when you want an extra set of hands!

Nash - who is building chits for his upcoming move

 

John,
It might not hurt to put a layer of Hondabond around the rubber gasket as well. I had a very small leak last time I took off the breather box and I did this in conjunction with replacing the rubber gasket. ...No leaks.

 

John
Look for any cracks first, I have had this problem before on a couple of my motors including bulldogs
Yes they can be a hassle to get out on the b18s
If there are no cracks replace the o ring and apply a liberal amount of the grey honda sealant and that should be the end of it
Iam currently building a fix for this problem which will elliminate the canister all together, and reroute the gasses to the catch can, there is a lot of oil at this location during race conditions
Do this fix and if there are any more problems call me
WCS Motorsports
Stormpower Race Engines
CRX Si #12

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by johng &raquo;</TD></TR><TR><TD CLASS="quote">I pick up a new breather box from Honda tomorrow. I'll cram it in this week and let you know.
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i believe you are on the right track!! we usually recommend replacing the box when we do them at the dealer.... definatly make sure you replace the hoses and any rubber components attached to it while you are already there

John i'm doing great almost into the new house
sup Nash

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by johng &raquo;</TD></TR><TR><TD CLASS="quote">I've taken the vacume line from the intake manifold that normally connects to the top portion of the PCV, and plugged it. I've ran another hose from to top of the PCV and ran it directly to a catch bottle. I</TD></TR></TABLE>

I think it's better to have some sort of vaccum pull on the crankcase though, isn't it? Otherwise pressure can possibly build up there. What I did on mine was plumbed in a water seperator for air tools using barb connectors in the hose from the intake manifold to the PCV valve.

Mine looks a little like the one on this page:

http://www.letterman.com.tw/airtool/Reguoiler.htm

Except mine has horizontal in & out ports where I screwed in the 1/4" barb fittings. It just kinda lays on my intake manifold there out of the way from anything, and in about 4 months collected probably 4-5 tablespoons of oil. Not the most elegant of solutions I'm sure, but it's cheap! ;-)

Just sharing,

Ryan P.

 

Well, that's definately one problem. The o-ring was broken. Once I finally got to it (what a pain), the whole box essentially fell off (it's normally tight as hell). I'll install the new breather box and o-ring tomorrow and post results. If this is the source of all my leak issues, this could mean the main seal and oil pump seal isn't leaking like I thought. That would be very good news.

 

ryan, it really doesnt need to be complicated. theres no possibility of positive pressure buildup in an open receptacle (bottle), and the negative pressure isnt needed to pull the oil out and trying to filter the oil vapor to put into the intake manifold still isnt accomplishing anything positive, so no need to bother.

 

Bringing this one back...

Honestly, how important is that breather can? I have seen a D16A6 from King Motorsports that had the PVC, and the oil breather can completely removed and then the hole in the block was plugged...

I would much rather plug the whole and remove everything and be done with it, but would like to know if that may lead to problems down the road..

Any thoughts?

 

ask TECH43 he seams to know everything!

 

lol.........

 

Think about how the stock setup worked on that motor. The line that goes from your valve cover to your intake tubing would feed "oily air" that would enter your intake manifold and that oily air (or what of it) would make it into the oil breather chamber.

If you no longer have this setup, meaning you have a catch can or breather tank so that this oily-air doesn't ever reach your intake manifold then you can/should remove the breather tank completely and plug all the appropriate holes. This is assuming it's a race engine. (safe assumption since it's johng)

BTW: What I have described is the case on the motor in my ITA crx that was built by King Motorsports and if you would like pictures I would be happy to supply them.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rice_classic &raquo;</TD></TR><TR><TD CLASS="quote">BTW: What I have described is the case on the motor in my ITA crx that was built by King Motorsports and if you would like pictures I would be happy to supply them.</TD></TR></TABLE>

Supply pics. How was the hole in the block plugged?

 

My first thought would be, if you plug the hole in the block where does the excess crankcase pressure go?? Seems to me there would be a buildup of crankcase pressure.

I agree, the use of a catch can is beneficial to a race motor because you are always giving the motor fresh air in the intake versus contaminated oily air from the crankcase breather. These are commonly installed in stock motors to help with emissions as I believe.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BluGTIVR &raquo;</TD></TR><TR><TD CLASS="quote">My first thought would be, if you plug the hole in the block where does the excess crankcase pressure go?? Seems to me there would be a buildup of crankcase pressure.
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My guess would be that the king motorsports engine had a crankcase breather in some other place.