# oil in the crank case breather...bad pcv?



## cptnsloni (Apr 17, 2002)

well i ahve oil in my intake area....took the intake hose off the other day and saw the throttle body with a coating of wet oil....never saw it there before....looked liek it was comign fromteh crank case breather....i think its a bad pcv valve...any other opinions?


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## vwboomer2 (Jan 26, 2003)

*Re: oil in the crank case breather...bad pcv? (cptnsloni)*

It's a common problem, and in the short time I've been 'contributing' on vortex I've seen it posted several times.
Put a 7/8" hose from home depot on the piece of the breather that normally goes to the intake tube and route it to the underside of the car. Plug the hole on the intake tube.
Now wash out the thing with simplegreen or brake cleaner or something.
It's not a _bad_ breather really, just a crappy design I guess.


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## TooLFan46n2 (Oct 18, 1999)

*Re: oil in the crank case breather...bad pcv? (vwboomer2)*

My car does the same thing. I believe there is a retrofit kit from VW that will fix the problem but it's quite expensive.


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## king_hil (Mar 4, 2003)

*Re: oil in the crank case breather...bad pcv? (vwboomer2)*

yeah, i've been wondering about this. i've been cleaning out the oil every now and then.
what exactly does the pcv do?
and you're saying take the 7/8ths hose and pop it onto the pcv and let it dangle?
i guess i'm still a bit confused cause i don't know what the pcv does. heh.
if we don't need that little thing, then buying a bigbore intake would be so much easier..don't have to worry about it.


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## cptnsloni (Apr 17, 2002)

*Re: oil in the crank case breather...bad pcv? (king_hil)*

its basically a check valve....lets oil pass through one way...if it breaks...oil can flow freely....in tern letting oil into the intake


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## king_hil (Mar 4, 2003)

*Re: oil in the crank case breather...bad pcv? (cptnsloni)*

heh, thanks, did a search for once. quite a bunch of interesting posts about this, esp the one with the air compresser filter.
good stuff.


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## Jettadrvr (Mar 18, 2003)

*Re: oil in the crank case breather...bad pcv? (king_hil)*

I found that when I put in my nice clean new K&N air filter the problem went away. Also, quick fix someone mentioned was to line up the arrows at each end on the breather tube that goes from the airbox to the intake. It makes the tube have a high spot about halfway that prevents the oil from draining back to the airbox.


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## Cubix (Jul 26, 2002)

*Re: oil in the crank case breather...bad pcv? (Jettadrvr)*

PCV Valve lets the gases formed by the oil heating out. If you ever looked at oil at it was white/milky, that means you have a bad PCV valve. VW (atleast MKIII) do not have PCV valves. They are known as T-Breathers but basically serve the same purpose. The reason you are getting oil in the intake hose is because it is over saturated with oil residue. 40 bucks to replace









Go with the length of hose as stated above. VW sells a retro fit kit that electronically closes the valve when the car is turned off (because this is when it actually leaks)
Not worth it, like I said, just get the hose http://****************.com/smile/emthup.gif


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## zuren (Sep 26, 2000)

*Re: oil in the crank case breather...bad pcv? (Cubix)*


_Quote, originally posted by *Cubix* »_PCV Valve lets the gases formed by the oil heating out. If you ever looked at oil at it was white/milky, that means you have a bad PCV valve. VW (atleast MKIII) do not have PCV valves. They are known as T-Breathers but basically serve the same purpose. The reason you are getting oil in the intake hose is because it is over saturated with oil residue. 40 bucks to replace








Go with the length of hose as stated above. VW sells a retro fit kit that electronically closes the valve when the car is turned off (because this is when it actually leaks)
Not worth it, like I said, just get the hose http://****************.com/smile/emthup.gif 

I've never heard this explanation before. There are many threads on this, try a search...
Oil residue in the intake is a common Mk3 2.0 problem. As the oil heats up in the crankcase, vapor is produced and needs to be vented. It travels up that tubing to the Pressure Regulating Valve (PRV - #037129101H). To satisfy emissions regulations, VW routed that vapor and any vapor from the valve cover into the intake tube. As the engine is running, that vapor is sucked back into the engine to be burned. The residue problem begins once you turn the car off. That oil is still hot, gives off vapor, travels the route it is supposed to and gets into the intake tube. Now the vapor is just sitting there since the engine is off, cools, condenses, and leaves an oily mess behind.
There are a couple ways to deal with the mess:
1. Buy the VW intake tube retrofit kit that has an electrically controlled valve that closes once the engine is off to keep oil vapor out of the intake - ~$140 and still needs to be installed and wired.
2. Rig some type of oil separator filter (eg. air compressor style) inline with the tubing. - cost may vary
3. Clean the intake tube every once in a while with a degreaser - $3.99 for a bottle of Simple Green
4. Put a blocking plate on the crankcase opening and install a valve cover breather filter - This is ILLEGAL since you are now venting the vapors directly into the environment. I doubt you would pass an emissions test if they saw it.
I've never heard of a PCV (or PRV, as VW calls it) causing any moisture (milky material in oil) contamination. That is caused by taking too many short trips and not allowing the oil to heat hot enough to burn off contaminants. I suppose if the rubber grommet on the PRV wasn't sealing, moisture could get in, but not the PRV itself.
Changing hoses will not eliminate the problem. It wouldn't matter if the hose is new or old, as long as there is a passage-way for the vapor to get to the intake tube, you will get a residue buildup.
I may try an oil separator at some point but for now I say clean it every oil change. I would clean your throttle body at the same time since the vapor can gum that up and give you a "idle adaptation at limit" CEL. Hope this helps 


_Modified by zuren1cs at 11:54 PM 5-5-2003_


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## TooLFan46n2 (Oct 18, 1999)

*Re: oil in the crank case breather...bad pcv? (zuren1cs)*

Good writeup http://****************.com/smile/emthup.gif


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## king_hil (Mar 4, 2003)

*Re: oil in the crank case breather...bad pcv? (TooLFan46n2)*

amen


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## rucavazos (Feb 11, 2010)

*Re: oil in the crank case breather...bad pcv? (king_hil)*

is this what a volks wagen service center would call a crancase breather valve. My engine light recently turned on and they said my cranckase breather valve need to be replaced. I have a 2006 jetta 2.5.


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## FL 2.0L (Aug 1, 2002)

That is the term the dealer uses. The hose at the front of the block is called the crankcase breather hose.


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## blacksanta (Aug 8, 2009)

*Re: (FL 2.0L)*

I'm sorry, I got confused as to what was the problem. Was it the crankcase breather hose or was it the pcv valve? My breather hose on my 94 jetta was totally cracked at the and behind the clip. I only noticed this after pools of oil started accumulating there. Replaced it with a kit from a local foreign auto parts store. cost $36. No more oil!!
As far as pcv valves go. I don't think my 94 obd-1 has a traditional pcv valve. Does it?


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## 97Duber (Feb 15, 2010)

*Re: oil in the crank case breather...bad pcv? (zuren)*

do u know how i would remove the breather off my 1997 jetta


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## dylangoeselectrk (May 16, 2009)

*Re: oil in the crank case breather...bad pcv? (97Duber)*

so what does having a bad pcv or prv valve do to your car?


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## J.R.Freeman (Apr 19, 2008)

My apologies if this has been said before: I'm heading to bed soon, and I'm too tired to wade through all the posts above!
Like you mentioned: a PCV check-valve failure could cause this issue. It is an inexpensive part, and I would start there.
JF


_Modified by J.R.Freeman at 5:58 PM 3-10-2010_


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## Robert Roberts (Jan 30, 2009)

*Re: (J.R.Freeman)*


_Quote, originally posted by *J.R.Freeman* »_My apologies if this has been said before: I'm heading to bed soon, and I'm too tired to wade through all the posts above!
Like you mentioned: a PCV check-valve failure could cause this issue. It is an inexpensive part, and I would start there.
JF

_Modified by J.R.Freeman at 5:58 PM 3-10-2010_

You didn't read the whole thread and you are recommending the replacement of the part as a start?!
BTW: For some people, $60 is NOT an inexpensive part.
Lose the pretentious attitude and do the required reading before handing out your questionable advice next time. Better still, keep quiet until you actually do know something useful to add besides debating the superiority of superchargers over turbos.


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## dylangoeselectrk (May 16, 2009)

*Re: (Robert Roberts)*

im pretty sure my pcv is bad, the line pretty much crumbled in my hands. i made a make shift line out of some heater hose. will a bad pcv cause any damage id like to fix this asap but the budget is tight. so i am wondering is it something i should rush to fix


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## solidcustoms (Feb 2, 2010)

*Re: (dylangoeselectrk)*

why is no one recommending a catch can just asking what are some con's other then price and depending on your design you have to empty it


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## Robert Roberts (Jan 30, 2009)

*Re: (dylangoeselectrk)*


_Quote, originally posted by *dylangoeselectrk* »_im pretty sure my pcv is bad, the line pretty much crumbled in my hands. i made a make shift line out of some heater hose. will a bad pcv cause any damage id like to fix this asap but the budget is tight. so i am wondering is it something i should rush to fix

I would fix it or rig a catch can asap. Search and you will find ways to make them (catch cans) for next to nothing. They aren't emissions legal anywhere where they care though.
As for a bad PCV causing damage? It can if it is completely plugged and oil vapour has no where to go. If that happens, pressure builds up in the crancase and finds its own way out. Usually not one you want, like a crank seal for example.


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## dylangoeselectrk (May 16, 2009)

*Re: (Robert Roberts)*

what is the benefit of having a catch can?


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## Robert Roberts (Jan 30, 2009)

*Re: (dylangoeselectrk)*


_Quote, originally posted by *dylangoeselectrk* »_what is the benefit of having a catch can?

You rig it to catch the condensed oil vapour vented from the crankcase.
You would use it in place of the PCV until you can replace the PCV and hoses etc...
The PCV directs the condensed vapour into the intake boot where it gets carried along with the intake air into the engine, where it is burned up (part of emissions).
The can just collects it.


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## J.R.Freeman (Apr 19, 2008)

*Re: (Robert Roberts)*


_Quote, originally posted by *Robert Roberts* »_
Lose the pretentious attitude and do the required reading before handing out your questionable advice next time. Better still, keep... 


Wow, how do you really feel?







Let's try to keep it on a professional level.


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## J.R.Freeman (Apr 19, 2008)

*Re: (dylangoeselectrk)*


_Quote, originally posted by *dylangoeselectrk* »_im pretty sure my pcv is bad, the line pretty much crumbled in my hands. i made a make shift line out of some heater hose. will a bad pcv cause any damage id like to fix this asap but the budget is tight. so i am wondering is it something i should rush to fix

Hi Dylan,
Your heater hose should be fine as long as it is rated for corrosive fluids - some soft rubber lines have something like 'safe for gasoline' written on them. 
I like the catch can idea, but if you can swing it, it would be best to get your PCV system in good shape as soon as you can. Ingesting a little oil is not a big deal (for the engine anyway!) but over time it can lead to plug fouling, build-up on the valves among other things, and could damage your catalytic converter down the road.
Best of luck Dylan, let us know how it goes.
JF


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## dylangoeselectrk (May 16, 2009)

*Re: (J.R.Freeman)*

thanks for the help i got a new (used but in great condition ) line from a local junk yard for ten bucks







. but now im trying to find a good deal on the valve. it seems like a bad idea to get a used valve is this true?


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## J.R.Freeman (Apr 19, 2008)

*Re: (dylangoeselectrk)*


_Quote, originally posted by *dylangoeselectrk* »_thanks for the help i got a new (used but in great condition ) line from a local junk yard for ten bucks







. but now im trying to find a good deal on the valve. it seems like a bad idea to get a used valve is this true?

Hey Dylan,
Good find! Hmm... it depends on the condition of the valve I guess. I thought they weren't too expensive new, but I may be wrong about that.
The PCV check valves I am familiar with (the common variety I guess) are made up of a little cylinder with an opening on both ends, a little trap door (the valve part) and a spring. I think the idea is that once the pressure in the crank-case (or under the valve cover) is high enough, it forces the trap door off of its seat and vents into the intake system. I think the valve assembly also contains some baffling to try and keep oil out.
All that to say, if a modern VW valve is similar, you might be able to get a used one and just clean it up. I fixed a traditional style one before by simply soaking it in paint thinner over night. It had stuck closed after it had gummed up with sludge. I'm not sure that it was as good as new, but it corrected the blow-by issue I was having, thankfully! This was on an early 90's Sonata though.
JF


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## dylangoeselectrk (May 16, 2009)

*Re: (J.R.Freeman)*

J.R. you've been super helpful thank you. i might try to just soak mine. There not too expensive like 62 from vw. but moneys tight. hopefully the paint thinner works out. then i can move on down the list of isht to be fixed.


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