function of breather-pcv valve 1995 VR6 12V AAA

hi all, This is regarding an infamously fragile piece at the top of
the valve cover, tying the crankcase ventilation system together.

My question is whether someone can verify the function of this valve -
in particular the reason for having the line from the charcoal
canister to the throttle body tee-d into it. I have searched for
hours online and still have not found two sources to say the same
thing.

The part in question starts at the valve cover near the front of the
engine and has a valve with unknown function and continues to a
heating element and there on into the air intake hose prior to the
throttle body and after the MAF.

The reason I am asking about this ( in addition to my own curiosity)
is that the part is >$100 to replace because VW makes it only
available as a large assembly containing the intake tube, heating
element, valve and all the tubes. (no thanks, vW!).

I have the Bentley and they call this the "PCV breather valve". My
problem is that I cannot determine whether this is the "PCV Valve" end
if the circuit where the air leaves the crankcase or wether it is the
Breather side of the circuit where the air enters the crankcase.

I also do not understand why it is coupled to the charcoal canister-
throttle body line.

I am considering seperating the two and installing a simple PCV check
valve between the valve cover and air intake, and plugging off the tee-
hose that comes out of the charcoal-canister vent.

On Mar 4, 9:46 am, "Mark" <glenparkcourt-vwtoyota... (AT) yahoo (DOT) com> wrote:

hi all, This is regarding an infamously fragile piece at the top of
the valve cover, tying the crankcase ventilation system together.

My question is whether someone can verify the function of this valve -
in particular the reason for having the line from the charcoal
canister to the throttle body tee-d into it. I have searched for
hours online and still have not found two sources to say the same
thing.

The part in question starts at the valve cover near the front of the
engine and has a valve with unknown function and continues to a
heating element and there on into the air intake hose prior to the
throttle body and after the MAF.

The reason I am asking about this ( in addition to my own curiosity)
is that the part is >$100 to replace because VW makes it only
available as a large assembly containing the intake tube, heating
element, valve and all the tubes. (no thanks, vW!).

I have the Bentley and they call this the "PCV breather valve". My
problem is that I cannot determine whether this is the "PCV Valve" end
if the circuit where the air leaves the crankcase or wether it is the
Breather side of the circuit where the air enters the crankcase.

I also do not understand why it is coupled to the charcoal canister-
throttle body line.

I am considering seperating the two and installing a simple PCV check
valve between the valve cover and air intake, and plugging off the tee-
hose that comes out of the charcoal-canister vent.

I am still trying to figure this out. I would like to ask a more
simple question. Is this breather/pcv valve (at the top of the valve
cover) the Inlet to the engine crankcase or is the Outlet or is it
both?
My understanding of a PCV system is that there should be an inlet
under low negative pressure and an outlet under high negative pressure
with air flowing through the crankcase. The air going in should be
filtered and the air going out should go into the combustion air.

I have looked around the engine and I can only find this one location
for air to move in or out? of the crankcase. what am I missing?

thanks!

just fix it with the correct parts! As for the hose, it most likely just
connects there for/from the purge valve.

"Mark" <glenparkcourt-vwtoyotavr6 (AT) yahoo (DOT) com> wrote

On Mar 4, 9:46 am, "Mark" <glenparkcourt-vwtoyota... (AT) yahoo (DOT) com> wrote:
hi all, This is regarding an infamously fragile piece at the top of
the valve cover, tying the crankcase ventilation system together.

My question is whether someone can verify the function of this valve -
in particular the reason for having the line from the charcoal
canister to the throttle body tee-d into it. I have searched for
hours online and still have not found two sources to say the same
thing.

The part in question starts at the valve cover near the front of the
engine and has a valve with unknown function and continues to a
heating element and there on into the air intake hose prior to the
throttle body and after the MAF.

The reason I am asking about this ( in addition to my own curiosity)
is that the part is >$100 to replace because VW makes it only
available as a large assembly containing the intake tube, heating
element, valve and all the tubes. (no thanks, vW!).

I have the Bentley and they call this the "PCV breather valve". My
problem is that I cannot determine whether this is the "PCV Valve" end
if the circuit where the air leaves the crankcase or wether it is the
Breather side of the circuit where the air enters the crankcase.

I also do not understand why it is coupled to the charcoal canister-
throttle body line.

I am considering seperating the two and installing a simple PCV check
valve between the valve cover and air intake, and plugging off the tee-
hose that comes out of the charcoal-canister vent.

I am still trying to figure this out. I would like to ask a more
simple question. Is this breather/pcv valve (at the top of the valve
cover) the Inlet to the engine crankcase or is the Outlet or is it
both?
My understanding of a PCV system is that there should be an inlet
under low negative pressure and an outlet under high negative pressure
with air flowing through the crankcase. The air going in should be
filtered and the air going out should go into the combustion air.

I have looked around the engine and I can only find this one location
for air to move in or out? of the crankcase. what am I missing?

thanks!

On Mar 5, 8:20 pm, "Lost In Space/Woodchuck"
<newsgroupma... (AT) wildblue (DOT) net> wrote:

just fix it with the correct parts! As for the hose, it most likely just
connects there for/from the purge valve.

"Mark" <glenparkcourt-vwtoyota... (AT) yahoo (DOT) com> wrote in message

news:1173132374.570046.314970 (AT) t69g2000cwt (DOT) googlegroups.com...



On Mar 4, 9:46 am, "Mark" <glenparkcourt-vwtoyota... (AT) yahoo (DOT) com> wrote:
hi all, This is regarding an infamously fragile piece at the top of
the valve cover, tying the crankcase ventilation system together.

My question is whether someone can verify the function of this valve -
in particular the reason for having the line from the charcoal
canister to the throttle body tee-d into it. I have searched for
hours online and still have not found two sources to say the same
thing.

The part in question starts at the valve cover near the front of the
engine and has a valve with unknown function and continues to a
heating element and there on into the air intake hose prior to the
throttle body and after the MAF.

The reason I am asking about this ( in addition to my own curiosity)
is that the part is >$100 to replace because VW makes it only
available as a large assembly containing the intake tube, heating
element, valve and all the tubes. (no thanks, vW!).

I have the Bentley and they call this the "PCV breather valve". My
problem is that I cannot determine whether this is the "PCV Valve" end
if the circuit where the air leaves the crankcase or wether it is the
Breather side of the circuit where the air enters the crankcase.

I also do not understand why it is coupled to the charcoal canister-
throttle body line.

I am considering seperating the two and installing a simple PCV check
valve between the valve cover and air intake, and plugging off the tee-
hose that comes out of the charcoal-canister vent.

I am still trying to figure this out. I would like to ask a more
simple question. Is this breather/pcv valve (at the top of the valve
cover) the Inlet to the engine crankcase or is the Outlet or is it
both?
My understanding of a PCV system is that there should be an inlet
under low negative pressure and an outlet under high negative pressure
with air flowing through the crankcase. The air going in should be
filtered and the air going out should go into the combustion air.

I have looked around the engine and I can only find this one location
for air to move in or out? of the crankcase. what am I missing?

thanks!- Hide quoted text -

- Show quoted text -

Thanks for taking the time, Woodchuck. Unfortunately for me, if I
always fixed my VW with 'the correct' parts I wouldn not be able to
afford the car-literally!. I have to be careful what to spend money
on. (I'll avoid going off on a rant about B4 VR6's for now) After
further reading and searching I think I found that there is NOT a
fresh air inlet for the Crankcase ventilation on this engine and the
area in question (breather) is meant to evacuate the crankcase either
through the big tube to the air intake hose or through the small hose
into the throttle body. The particulars of operation under all
conditions is hard to understand and does not seem to be common
knowledge to people on the net.

Yes, VW's are pricy to keep going and I don't like to spend money either,
but sometimes you must to prevent problems down the road. And yes, VW uses a
"closed" crankcase breather system which I think is the same with all other
car/trucks. I'm sure it's a federal emission thing and has been for many
years


"Mark" <glenparkcourt-vwtoyotavr6 (AT) yahoo (DOT) com> wrote

On Mar 5, 8:20 pm, "Lost In Space/Woodchuck"
newsgroupma... (AT) wildblue (DOT) net> wrote:
just fix it with the correct parts! As for the hose, it most likely just
connects there for/from the purge valve.

"Mark" <glenparkcourt-vwtoyota... (AT) yahoo (DOT) com> wrote in message

news:1173132374.570046.314970 (AT) t69g2000cwt (DOT) googlegroups.com...



On Mar 4, 9:46 am, "Mark" <glenparkcourt-vwtoyota... (AT) yahoo (DOT) com> wrote:
hi all, This is regarding an infamously fragile piece at the top of
the valve cover, tying the crankcase ventilation system together.

My question is whether someone can verify the function of this valve -
in particular the reason for having the line from the charcoal
canister to the throttle body tee-d into it. I have searched for
hours online and still have not found two sources to say the same
thing.

The part in question starts at the valve cover near the front of the
engine and has a valve with unknown function and continues to a
heating element and there on into the air intake hose prior to the
throttle body and after the MAF.

The reason I am asking about this ( in addition to my own curiosity)
is that the part is >$100 to replace because VW makes it only
available as a large assembly containing the intake tube, heating
element, valve and all the tubes. (no thanks, vW!).

I have the Bentley and they call this the "PCV breather valve". My
problem is that I cannot determine whether this is the "PCV Valve" end
if the circuit where the air leaves the crankcase or wether it is the
Breather side of the circuit where the air enters the crankcase.

I also do not understand why it is coupled to the charcoal canister-
throttle body line.

I am considering seperating the two and installing a simple PCV check
valve between the valve cover and air intake, and plugging off the
tee-
hose that comes out of the charcoal-canister vent.

I am still trying to figure this out. I would like to ask a more
simple question. Is this breather/pcv valve (at the top of the valve
cover) the Inlet to the engine crankcase or is the Outlet or is it
both?
My understanding of a PCV system is that there should be an inlet
under low negative pressure and an outlet under high negative pressure
with air flowing through the crankcase. The air going in should be
filtered and the air going out should go into the combustion air.

I have looked around the engine and I can only find this one location
for air to move in or out? of the crankcase. what am I missing?

thanks!- Hide quoted text -

- Show quoted text -


Thanks for taking the time, Woodchuck. Unfortunately for me, if I
always fixed my VW with 'the correct' parts I wouldn not be able to
afford the car-literally!. I have to be careful what to spend money
on. (I'll avoid going off on a rant about B4 VR6's for now) After
further reading and searching I think I found that there is NOT a
fresh air inlet for the Crankcase ventilation on this engine and the
area in question (breather) is meant to evacuate the crankcase either
through the big tube to the air intake hose or through the small hose
into the throttle body. The particulars of operation under all
conditions is hard to understand and does not seem to be common
knowledge to people on the net.

On 5 Mar 2007 14:06:14 -0800, "Mark" <glenparkcourt-vwtoyotavr6 (AT) yahoo (DOT) com> wrote:

On Mar 4, 9:46 am, "Mark" <glenparkcourt-vwtoyota... (AT) yahoo (DOT) com> wrote:
hi all, This is regarding an infamously fragile piece at the top of
the valve cover, tying the crankcase ventilation system together.

http://replacement.car-stuff.com/par...howdc=true#top
$34 plus s/h i think this the part - if you want to replace w/o denting the wallet
as much

My question is whether someone can verify the function of this valve -
in particular the reason for having the line from the charcoal
canister to the throttle body tee-d into it. I have searched for
hours online and still have not found two sources to say the same
thing.

The part in question starts at the valve cover near the front of the
engine and has a valve with unknown function and continues to a
heating element and there on into the air intake hose prior to the
throttle body and after the MAF.

The reason I am asking about this ( in addition to my own curiosity)
is that the part is >$100 to replace because VW makes it only
available as a large assembly containing the intake tube, heating
element, valve and all the tubes. (no thanks, vW!).

I have the Bentley and they call this the "PCV breather valve". My
problem is that I cannot determine whether this is the "PCV Valve" end
if the circuit where the air leaves the crankcase or wether it is the
Breather side of the circuit where the air enters the crankcase.

I also do not understand why it is coupled to the charcoal canister-
throttle body line.

I am considering seperating the two and installing a simple PCV check
valve between the valve cover and air intake, and plugging off the tee-
hose that comes out of the charcoal-canister vent.

I am still trying to figure this out. I would like to ask a more
simple question. Is this breather/pcv valve (at the top of the valve
cover) the Inlet to the engine crankcase or is the Outlet or is it
both?
My understanding of a PCV system is that there should be an inlet
under low negative pressure and an outlet under high negative pressure
with air flowing through the crankcase. The air going in should be
filtered and the air going out should go into the combustion air.

I have looked around the engine and I can only find this one location
for air to move in or out? of the crankcase. what am I missing?

thanks!

On Wed, 07 Mar 2007 11:57:51 GMT, samstone (AT) aol (DOT) com wrote:

http://replacement.car-stuff.com/par...howdc=true#top
$34 plus s/h i think this the part - if you want to replace w/o denting the wallet
as much

So sorry , i had the wrong year/mod i started here looking for something
else oops!!! http://www.car-stuff.com/

On Mar 7, 6:04 am, samst... (AT) aol (DOT) com wrote:

On Wed, 07 Mar 2007 11:57:51 GMT, samst... (AT) aol (DOT) com wrote:
http://replacement.car-stuff.com/par...jsp?year=2000&...
$34 plus s/h i think this the part - if you want to replace w/o denting the wallet
as much

So sorry , i had the wrong year/mod i started here looking for something
else oops!!! http://www.car-stuff.com/

I think I figured out part of my confusion. the INLET that I was
looking for may be present only on V6 or V8 or other Vee type engines
that have two seperate valve covers. On those engines, one valve
cover has an inlet that draws fresh air from the air cleaner and the
other valve cover has the pcv valve and is connected to the throttle
body. This keeps both sides of the engine vented and the air only
moves in one direction. On a VR6 or four cylinder engine there
apparantly is only an outlet and the inlet is the blowby that comes
from the combustion chambers.

btw, the cost on car-stuf.com is very high ~ $164. If I buy the part,
I will go to worldimpex.com where the part is $106 if I buy the warm
climate model and subsitute in my heating element.

I had to purchase one for a '97 VR6 engine and it cost between $100-200 for
the entire hose from the MAF to the intake manifold. It seems like you have
to purchase the whole kit to replace that PCV hose and valve. :-(
AND they might have a few different types so make sure you research which
one you have.
I am with Lost In Space, put on the right one and don't worry about it for
another 10 years or so.
Or maybe the junkyard if you are lucky. ;-)
--
later,
dave
(One out of many daves)


<samstone (AT) aol (DOT) com> wrote

On Wed, 07 Mar 2007 11:57:51 GMT, samstone (AT) aol (DOT) com wrote:

http://replacement.car-stuff.com/par...howdc=true#top
$34 plus s/h i think this the part - if you want to replace w/o
denting the wallet
as much

So sorry , i had the wrong year/mod i started here looking for something
else oops!!! http://www.car-stuff.com/