Clean breather box Honda Civic (oil separator) - Backyard Mechanic DIY

[@mengxiangxuan6552]

i gotta say this is the best voiceover quality from a video this old

[@aletapearce2369]

I did this today. Thanks much for the post. You made it super easy for me. And it was super easy. I replaced all the old PVC parts in line of this, except the upper hose, which was still good. That plus some fresh plugs, cap and rotor. It's like I have a new car now ;-) I'm reasonably certain that part hasn't been clean since it was new, in 1992. It was ultra funky in there.

[@MikeKollin]

Question: After you cleaned it, did you just bolt it back on or do you have to put a layer of sealant all the way around it. My mechanic says you have to put a layer of sealant on it and I saw a video of a much newer car that did this. But No one talks about it other than them. I would greatly appreciate the answer. I ordered the O Ring and the connector hoses to the breather box and they will be here next week. Again thanks if you can let me know!

[@benfroggg]

I'm not sure what your question is, but I think you are asking what the breather box does- The box separates oil from air in the back of the engine. The need for this is that stray exhaust gasses can build up in the crankcase and blow seals and such. The crankcase must be vented but not to atmosphere as it contains unburned hydrocarbons. It's then sucked into the intake manifold. Thus, it needs to be free of oil so your intake stays clean and the fuel mix stays accurate. Hope that helps. B

[@stan2880]

Thank you for this video. The support bracket for the manifold makes it easier to separate the intake manifold from the head when you change your intake manifold gasket. I know this because I had to change it 2 times, once with the bracket on and once without it on. The second time was a lot harder and I was scared I would damage the intake from prying it off.

[@5PYZ3R]

Doing a top end build, removing the intake mount and cleaning the PCV system while I'm at it. This video is great man, thanks.

[@benfroggg]

You're welcome! Good luck on your project. That's more adventurous than I'm willing to get on my old Honda~

[@williamh7122]

I was able to remove and put back the breather chamber in my 98 CX hatchback, thank you for this video.

[@benfroggg]

Glad to help. you're welcome.

[@benfroggg]

Very good suggestion, and timely as I just pulled another VX motor that I will be doing this to in the next couple of days. I've been looking for a powerful degreaser, thanks! B

[@trickycruz6464]

What's the purpose of cleaning the breather box?

[@Bunta559]

great video! just finished doing the same thing and the car is running good now. good lookin out bro.

[@stan2880]

Did this on a 2000 civic. BEWARE the top bolt of the breather box is extremely difficult to get to. Unlike the 5th gen in the video, it is not able to be seen through the opening in the intake, it is located more the left under the actual part of the intake. It is difficult to get a ratchet in there with the manifold still on, even with an extension.

[@benfroggg]

@rholleba The VX has a highly disputed PCV valve. To my knowledge, some models had a straight valve (I believe 92 and 93 models) mounted in the breather box as mine was. The valve at 0:42 is not a valve, it's a hollow elbow. Many mechanics replace this elbow with a PCV valve, ignoring the actual PCV valve in the breather box. To make matters worse, 94 and up cars have a straight empty connector below and a PCV in the location you speak of. Message me FMI.

[@haqitman]

On my 92 Si there's a PCV where I think there should be an elbow, but possibly another PCV connected to the breather that's probably never been changed. This weekend i'm crawling under to find out. Thanks for this video!

[@autospacutlerbay]

Thanks for the video! This helped me a lot, and I've decided to hold off until it's time fore an oil change, easier access without the oil filter. I'll be doing mine soon due to an oil leak that I've traced back(up) to the breather box. I bought a new OEM o-ring, and a new PCV valve grommet. I'm assuming the o-ring is the culprit.

[@MikeKollin]

Where did you buy it, the O Ring? Is there anything else that needs to be replaced, etc? Is there a seal or Gasket to get? Thanks I am about to do this on my car...

[@shambop1]

Most helpful. Thanks for your video and instruction. It surely helped us on our '89 Civic. So glad we didn't try to fix it from the top. Thanks benfroggg

[@benfroggg]

Your welcome! This was one of my first videos that got popular on youtube. It's interesting that it's still helping people today!

[@nebmodo9635]

I know you did this a few years back but do you remember there being any kind of material in the breather chamber itsself? Mines just a hollow can. Dosnt make sense how it could sepperate liquid from vapor with out some kind of filter in there?

[@rholleba]

@benfroggg Interesting... I've seen many posts in the Honda Civic forums showing the PCV valve in the breather box. Not many talk about the PCV valve up top, like mine. So, I was a bit surprised when I looked under my hood. Thanks for the info. I'll be checking to see if I have a second pcv valve down there. I have no idea what the previous owners have done. Would having two PCV valves make a noticable difference?

[@MikeKollin]

What happened? Did you find a 2nd PCV Valve? I doing' think I have one on my 95 Del Sol... I ordered all the parts for under the PCV valve that connects to the Breather box and it didnt' show anything like a 2nd PCV Valve on the print out. 1 question. After you cleaned out the Breather Box, did you just put the O Ring on nad tighten the bolt down to the breather box / engine or did you have to put a Sealant around the entire breather box before connecting it to the engine? Someone said I don't have to do that nad another person my mechanic says you do...

[@d46512]

Thanks for the detailed video. Other than knowing you have a slightly less nasty engine, why perform this service? Will it help the seals last longer?

[@benfroggg]

Lower pressure in the crankcase will produce less leaking for sure. So if the PCV valve is particularly clogged, this should improve oil leaks. If the PCV valve is badly clogged, the dirty breather box could reclog the new PCV, etc. B

[@rholleba]

I've noticed that my breather box is coated with oil as well. So, thanks for the video. It helped to give me an idea what to do. However, my pcv valve appears to be mounted on the intake manifold and not on the side of the breather box. I thought I could see the same kind of thing on yours as well at 0:42, for a split second, but you were moving the camera too fast there. Is that right? In that case you'd have two pcv valves?

[@benfroggg]

@rholleba Two PCV valves wont hurt anything, or really help anything... unless one has failed. If it fails open, no big deal. If it fails closed, (and you didn't know it existed down below) there would be running/idle/driveability problems. Symptoms are slightly lower power, increased oil consumption/smoke, etc. B

[@MikeKollin]

Over the last 24 months I have replaces almost everything I can imagine on my D15B7 Del Sol Engine. New Plugs, Wires, Fixed IACV valve, replaced all hoses, Gas Filter, Air filter 3 months ago, PCV Valve, etc. etc. I just cleaned out the Map Sensor and Throttle body and holy shit that really #1 Added a lot of Power to the car and very responsive too! #2 MPG Went Way Back up to at least 41 Hwy 35+ City.... it's really fun to drive now. I also noticed, at least a year ago, that when the oil is at the full mark it kind of bogs it down when I get the RPM's past 4K. But when I let it go down a little bit below the full mark it can breath better and it doesn't struggle against itself like the air / power is flowing better and it goes even better, more power... Just ordered all the connecting parts from under the PCV to the Breather Box and also top rubber connector tube to the top tube that goes back into the Throttle body... I figured if all of this was clear and clean it could breath better and no back up pressure... So right now the engine is really zooming along with full power but when full of oil it kind of fights itself. But when oil goes below full mark, it has more free Power! Is that normal?

[@benfroggg]

@@MikeKollin Fascinating! Your logic makes sense to me... I've never had personal experience with overfill/lower power, but if the breather is pulling more oil through... that's going to mess with the a/f ratio for sure. I'm speculating, of course. But again, your logic makes sense to me.

[@MikeKollin]

@@benfroggg Thanks... yeah I noticed this a while back when I first get oil refill it kind of fights itself... not much but it's not totally free. Then after a month or so I notice suddenly it just has more Free Power and the fight is gone... just zooms better.

[@AndrewCramb]

Very helpful and well spoken. Thanks for the info man!

[@benfroggg]

I don't know if the euro VX's are the same, but they are likely identical. Either in the intake manifold location near cylinder 4 or plugged into the breather box. B

[@jlw7kid]

If i remove the breather box will oil or anything leak out ?

[@johnnyfan1987]

I tried to replace PCV valve (97 civic ),but it was broken. The front part fall into breather box, I am not sure whether this can cause any problem or not?

[@chestonanderson]

Why did you do this was your car smoking ?

[@joncannon3178]

Thanks for the informative video. Not a lot of information out there about breather boxes. You might consider investing in nitrile gloves when doing a job like this.

[@benfroggg]

Good call on gloves, but I'd rather not have more consumables than needed. My hands clean up pretty easily with regular dish soap (which of course is a consumable) and doesn't fill up landfills with disposable gloves. I do use them on occasion, however. I just hate the idea of a throw away culture.

[@fixit9888]

Does anyone know the part number for this "breather box" or oil/air separator? I can't seem to find the O-ring or the runner attachment. 2012 Civic LX. Thanks

[@benfroggg]

Glad you found the video helpful! B

[@invictusdg_reinvestor]

I need to do this to my 1999 civic si, should be same correct ? First time

[@williamsantiago7303]

Hey thanks for the video. I have a question, I bought me my first Honda March of this year. It's a 2015 Honda cr-v LX with the 2.4L with only 35,000 miles on it. My question is, the engine is a GDI deal and alot of people are saying to get a oil catch can for it to keep the valves from getting carbon build up but does my car come with a factory catch can like the one in your video or is that something different? Thumbs up on your video bud.

[@benfroggg]

I wish I knew man. I imagine the car does have at least a basic setup like this one... I think the main thing is how are you going to use the car. If you're using it as a daily driver, a catch can prolly isn't needed. On the other hand, If you're doing lots of engine mods, it's prolly a good idea.

[@williamsantiago7303]

@@benfroggg Hey buddy thanks for the fast reply and the info. Keep up the good work. Take care man, bye.

[@benfroggg]

@0hisofly Thanks a lot! I've heard good things about the d15z1 crx swaps... I'd like to modify an insight or prius to double the battery pack and make it plug in hybrid. Cheers! B

[@Daredevil-nj9rf]

Hey mate any tips on getting the top bolt off the breather box in a 97 civic cxi??? it is not accessible from the top???

[@scottzambrano9635]

He's not gonna give you any f****** tips because he's full of s***Because the top bolt doesn't come out without taking the manifold off with this fake a**Fucking video from another fake ass youtube or with their fake ass fucking video bullshit.... The f****** socket doesn't even fit between the bracket and the God. D*** bolt to put a socket in there to take it off. That's why he cut and edited the video.Cause he's full of shit

[@shannonredmayne2736]

I'm sorta new with changing out parts on my '95 honda civic. I've done the maintenance like oil changes, and distributor cap/rotor. I'm going to change my pcv valve, and i've watched your video. Very helpful, but I'm wondering where is the breather box and the valve. I've looked really hard and still couldn't find it. help, please.

[@Assertiveman]

This is why oil rings get worned faster people never maintenance the Pcv valve

[@orozcocris93]

what did you use to get to the upper bolt? for the life of me i cant get that bolt off. not enough leverage. i am using a standard 10 with two 3 inch extensions and i have mixed that with a universal joint and even tried a deep socket but cant seem to get it happy

[@benfroggg]

Whoops, pardon the time it's taken me to reply! I don't have a specific memory of what worked but I do remember it was a struggle! In other instances of not having enough leverage, it can be helpful to strike the head of the bold with a hammer a couple times with medium force. It may not be possible where the bolt is... I wonder if you could give it a wrap with a socket extension from under the car? If not, worse case you could pull the intake manifold to get it. That'd be hella no fun but it would work and would give you an opportunity to inspect your EGR system if still equipped. (they are often plugged up solid on these cars and it makes them run like crap without other mods). Good luck!

[@orozcocris93]

@@benfroggg thanks!

[@Daniel569]

how much would that increase the mpg? like what does it do

[@djrickstartv]

is this the D16Y7 engine ? anyway Can this valve suck oil into the intake manifold ? and if yes why ? my honda burns oil every morning and i suspect this is the problem, also im thinking about disconnecting this valve (hose) from the intake manifold to see if the problem stops

[@kenfrazee41]

I'm having same issue, blue smoke out exhaust when still warming up. Good compression and new valve stem seals but still smokes in morning. very possible it is pcv system issue.

[@plightn]

Would brake cleaner work?

[@josephfreeman1427]

Yeah just break clean it till its clean

[@kenfrazee41]

Mine was very dirty as well. I have been sucking oil out of it (lots of blue smoke out of tail pipe) but only when engine is halfway warmed up. Will the cleaning solve this prob?

[@benfroggg]

Hmm. Can't hurt to try it. But I'm not optimistic. I think blue smoke on warm up sounds more like rings or valves to me.

[@kenfrazee41]

Welp, so far no more oil through intake mani, seemed to do the trick. New rings and stem seals, even compression readings, but still had those initial puffs of blue. Did learn the hard way that the cleaning gas must be blown out of breather, took an hour to unflood engine.

[@benfroggg]

Well then. That's a drag about the flooding. I didn't run into that with mine, not sure why you did. One other thing that strikes me... have you ever cleaned the EGR ports? I'm not sure it would matter on a cold engine (cant remember if the EGR valve opens before full warmup or not) but I do know when they are clogged they can cause problems related to fuel/air mix. Oh, and also- My car had a straight PCV valve that seated directly into the breather box. It looks like it's just a hose terminal thing but it's actually the PCV. Most cars have them more accessable than the 5th Gen civics. I have seen cars where someone removed the upper elbow (where the PCV vac line goes through the intake manifold before connecting to near the throttle body) and mistakenly installed an elbow PCV that some shop sold them. I found that certain shops had the wrong listing. Now, why that matters. If someone put one in where it didn't belong, it shouldn't matter. However, what DIDNT happen was a replacement of the ACTUAL PCV valve. Did you replace yours while you were cleaning the box? Seems like you did since the leftover gas flooded your engine (or at least the existing PCV was not clogged). If you didn't, you should. They are a one way valve and if it failed open, it MIGHT cause the blue smoke.... but this is speculation. Regardless, it's a common tuneup part. Good luck!

[@kenfrazee41]

Will have to look into the elbow deal. My 95 came with the valve at that location on the intake mani, which I replaced but now am wondering if that was even a factory part. I think that the breather box was just full of crap that was getting sucked through valve. This y8/b7 minime sees 7500 rpm everyday (I drive crappy).

[@benfroggg]

I wish I knew which models had the weird PCV. This is a VX with a D15z1. Not sure if yours would be this way or not. Definitely worth investigating.

[@carlos2kv]

can anyone help? that does essentially the breathing of the block box?

[@0hisofly]

Just found your channel, your civic is great man and inspiring for sure. I want to do a d15z1 swap someday in my crx

[@benfroggg]

Thanks! Glad it helped. B

[@kinoaskals2904]

do i need to drain the oil first or not before cleaning it?

[@benfroggg]

I don't know, but I don't think so. In the case of the video, I was doing this during an oil change. This made it much easer to access bolts on the breather box. So at the very least, you'd have to remove the oil filter and lose the fluid in it, so you might as well drain the rest of the oil while you're at it.

[@kinoaskals2904]

benfroggg Thanx man

[@benfroggg]

You're welcome.

[@bassiejnl]

Where can i find the PCV valve? i have a 92 civic VEI (european vx)

[@mushy18100]

bassiejnl go to your local Honda dealership

[@ThomasLorenz]

Interesting - now I know what to expect ... :) BTW I'd really consider wearing good gloves doing this shit...

[@silfortytypex]

So another oring can be found easily at a local auto store for what, a dollar or less, get a new one so you don't have to "worry" about that one going bad, its also something that I like to call "preventive maintenence." Thanks though for the cleaning explanation because I'm thinking about doing the same thing right about meow.

[@benfroggg]

Generally, I try to replace worn out parts when possible. But the gasket in question still hasn't leaked and it's been probably 30k since that video. The price of the replacement isn't the issue, the issue for me is that why replace something that isn't broken? I hear what you'r saying, though. Cheers!

[@silfortytypex]

I just did the same to my '99 Nissan Primera. I used a fuel cleaner solvent since I didn't have some old gas to put in there; worked about the same. Reddish oil came out of mine at first before the 2nd and 3rd application which made it clear. Also if you get the chance to do so mate I'd recommend that you take apart your Idle Air Control Valve and clean it out. My car idles very smooth now with both cleanings done!

[@benfroggg]

Good call on the IACV. I have cleaned mine in the two civics in the driveway. It sure does help the idle.

[@silfortytypex]

Here's another tip for ya I'd recommend replacing any and all vacuum lines and vacuum hoses that you can get to easy enough without lifting the car. Replace them with the same diameter hose as the original' even if the factory one feels fine, now you have the piece of mind that you won't have a vacuum leak that can cause a cylinder misfire code or ruin your economy and/or mess your idle up for another 100k miles or more depending on the hose. You might be surprised and find out that you may have fixed a small leak, if nothing more its cheap and always helpful!

[@benfroggg]

That is on my list due to your suggestion. Vac hose is cheap and my idle still sucks after a long drive. Thanks!

[@rickyg4800]

Try this today could not take off that top bolt!!!

[@benfroggg]

It's in a really tough spot for sure.

[@benfroggg]

Can't believe I missed this comment! No, I don waste beer. Ever. B

[@carlos2kv]

hi bro...thanks ok .. so in engine there are two breather in the valve cover and the crankcase!!! ohhh thanks againg...i will buy a catch can oil ....because honda make a error...ahhaha the oil ..because it pollutes the admission