PCV rattle 98 JGC 5.2
01-30-2006 | 09:32 PM
#11
Guest
Posts: n/a
Re: PCV rattle 98 JGC 5.2
There are actually two different PCV valve designs for the Mopar SB, one
with and one without a spring. I've also found that they may carry the same
part number because I suspect they peform almost identically once in
service. The one without the spring, however, is quite noisy as you have
discovered.
I've also come to believe that there is very little that breaks on a PCV
valve that might require its replacement, short of a broken spring. What
does happen is that they clog up and could use a good cleaning from time to
time. A little blast of WD-40 followed by brake cleaner and they're good as
new.
Oh, and you can tell the ones without the spring before you buy them by
shaking the package. The weight moves freely if there is no spring.
My 2 cents.
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:43DAD5BF.1281BBE2@sympatico.ca...
> The factory likely forgot to put in the spring or the wrong spring or
> something like that. Things 'do' come broken right out of the box.....
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> (More Off Road album links at bottom of the view page)
>
> JRK58@MSN.COM wrote:
>>
>> Hello Bill, I'm not real sure how close to intake port it is. I just
>> replaced it and it's not doing it anymore. Pretty weird, I've never
>> seen anything like it.
>>
>> Take care, JK
with and one without a spring. I've also found that they may carry the same
part number because I suspect they peform almost identically once in
service. The one without the spring, however, is quite noisy as you have
discovered.
I've also come to believe that there is very little that breaks on a PCV
valve that might require its replacement, short of a broken spring. What
does happen is that they clog up and could use a good cleaning from time to
time. A little blast of WD-40 followed by brake cleaner and they're good as
new.
Oh, and you can tell the ones without the spring before you buy them by
shaking the package. The weight moves freely if there is no spring.
My 2 cents.
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:43DAD5BF.1281BBE2@sympatico.ca...
> The factory likely forgot to put in the spring or the wrong spring or
> something like that. Things 'do' come broken right out of the box.....
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> (More Off Road album links at bottom of the view page)
>
> JRK58@MSN.COM wrote:
>>
>> Hello Bill, I'm not real sure how close to intake port it is. I just
>> replaced it and it's not doing it anymore. Pretty weird, I've never
>> seen anything like it.
>>
>> Take care, JK
01-30-2006 | 09:32 PM
#12
Guest
Posts: n/a
Re: PCV rattle 98 JGC 5.2
There are actually two different PCV valve designs for the Mopar SB, one
with and one without a spring. I've also found that they may carry the same
part number because I suspect they peform almost identically once in
service. The one without the spring, however, is quite noisy as you have
discovered.
I've also come to believe that there is very little that breaks on a PCV
valve that might require its replacement, short of a broken spring. What
does happen is that they clog up and could use a good cleaning from time to
time. A little blast of WD-40 followed by brake cleaner and they're good as
new.
Oh, and you can tell the ones without the spring before you buy them by
shaking the package. The weight moves freely if there is no spring.
My 2 cents.
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:43DAD5BF.1281BBE2@sympatico.ca...
> The factory likely forgot to put in the spring or the wrong spring or
> something like that. Things 'do' come broken right out of the box.....
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> (More Off Road album links at bottom of the view page)
>
> JRK58@MSN.COM wrote:
>>
>> Hello Bill, I'm not real sure how close to intake port it is. I just
>> replaced it and it's not doing it anymore. Pretty weird, I've never
>> seen anything like it.
>>
>> Take care, JK
with and one without a spring. I've also found that they may carry the same
part number because I suspect they peform almost identically once in
service. The one without the spring, however, is quite noisy as you have
discovered.
I've also come to believe that there is very little that breaks on a PCV
valve that might require its replacement, short of a broken spring. What
does happen is that they clog up and could use a good cleaning from time to
time. A little blast of WD-40 followed by brake cleaner and they're good as
new.
Oh, and you can tell the ones without the spring before you buy them by
shaking the package. The weight moves freely if there is no spring.
My 2 cents.
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:43DAD5BF.1281BBE2@sympatico.ca...
> The factory likely forgot to put in the spring or the wrong spring or
> something like that. Things 'do' come broken right out of the box.....
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> (More Off Road album links at bottom of the view page)
>
> JRK58@MSN.COM wrote:
>>
>> Hello Bill, I'm not real sure how close to intake port it is. I just
>> replaced it and it's not doing it anymore. Pretty weird, I've never
>> seen anything like it.
>>
>> Take care, JK
01-30-2006 | 09:32 PM
#13
Guest
Posts: n/a
Re: PCV rattle 98 JGC 5.2
There are actually two different PCV valve designs for the Mopar SB, one
with and one without a spring. I've also found that they may carry the same
part number because I suspect they peform almost identically once in
service. The one without the spring, however, is quite noisy as you have
discovered.
I've also come to believe that there is very little that breaks on a PCV
valve that might require its replacement, short of a broken spring. What
does happen is that they clog up and could use a good cleaning from time to
time. A little blast of WD-40 followed by brake cleaner and they're good as
new.
Oh, and you can tell the ones without the spring before you buy them by
shaking the package. The weight moves freely if there is no spring.
My 2 cents.
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:43DAD5BF.1281BBE2@sympatico.ca...
> The factory likely forgot to put in the spring or the wrong spring or
> something like that. Things 'do' come broken right out of the box.....
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> (More Off Road album links at bottom of the view page)
>
> JRK58@MSN.COM wrote:
>>
>> Hello Bill, I'm not real sure how close to intake port it is. I just
>> replaced it and it's not doing it anymore. Pretty weird, I've never
>> seen anything like it.
>>
>> Take care, JK
with and one without a spring. I've also found that they may carry the same
part number because I suspect they peform almost identically once in
service. The one without the spring, however, is quite noisy as you have
discovered.
I've also come to believe that there is very little that breaks on a PCV
valve that might require its replacement, short of a broken spring. What
does happen is that they clog up and could use a good cleaning from time to
time. A little blast of WD-40 followed by brake cleaner and they're good as
new.
Oh, and you can tell the ones without the spring before you buy them by
shaking the package. The weight moves freely if there is no spring.
My 2 cents.
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:43DAD5BF.1281BBE2@sympatico.ca...
> The factory likely forgot to put in the spring or the wrong spring or
> something like that. Things 'do' come broken right out of the box.....
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> (More Off Road album links at bottom of the view page)
>
> JRK58@MSN.COM wrote:
>>
>> Hello Bill, I'm not real sure how close to intake port it is. I just
>> replaced it and it's not doing it anymore. Pretty weird, I've never
>> seen anything like it.
>>
>> Take care, JK
01-30-2006 | 10:22 PM
#14
Guest
Posts: n/a
Re: PCV rattle 98 JGC 5.2
There's absolutely no way it would work without a spring to open
the valve at low open throttle vacuum!
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
RCSnyder wrote:
>
> There are actually two different PCV valve designs for the Mopar SB, one
> with and one without a spring. I've also found that they may carry the same
> part number because I suspect they peform almost identically once in
> service. The one without the spring, however, is quite noisy as you have
> discovered.
>
> I've also come to believe that there is very little that breaks on a PCV
> valve that might require its replacement, short of a broken spring. What
> does happen is that they clog up and could use a good cleaning from time to
> time. A little blast of WD-40 followed by brake cleaner and they're good as
> new.
>
> Oh, and you can tell the ones without the spring before you buy them by
> shaking the package. The weight moves freely if there is no spring.
>
> My 2 cents.
the valve at low open throttle vacuum!
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
RCSnyder wrote:
>
> There are actually two different PCV valve designs for the Mopar SB, one
> with and one without a spring. I've also found that they may carry the same
> part number because I suspect they peform almost identically once in
> service. The one without the spring, however, is quite noisy as you have
> discovered.
>
> I've also come to believe that there is very little that breaks on a PCV
> valve that might require its replacement, short of a broken spring. What
> does happen is that they clog up and could use a good cleaning from time to
> time. A little blast of WD-40 followed by brake cleaner and they're good as
> new.
>
> Oh, and you can tell the ones without the spring before you buy them by
> shaking the package. The weight moves freely if there is no spring.
>
> My 2 cents.
01-30-2006 | 10:22 PM
#15
Guest
Posts: n/a
Re: PCV rattle 98 JGC 5.2
There's absolutely no way it would work without a spring to open
the valve at low open throttle vacuum!
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
RCSnyder wrote:
>
> There are actually two different PCV valve designs for the Mopar SB, one
> with and one without a spring. I've also found that they may carry the same
> part number because I suspect they peform almost identically once in
> service. The one without the spring, however, is quite noisy as you have
> discovered.
>
> I've also come to believe that there is very little that breaks on a PCV
> valve that might require its replacement, short of a broken spring. What
> does happen is that they clog up and could use a good cleaning from time to
> time. A little blast of WD-40 followed by brake cleaner and they're good as
> new.
>
> Oh, and you can tell the ones without the spring before you buy them by
> shaking the package. The weight moves freely if there is no spring.
>
> My 2 cents.
the valve at low open throttle vacuum!
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
RCSnyder wrote:
>
> There are actually two different PCV valve designs for the Mopar SB, one
> with and one without a spring. I've also found that they may carry the same
> part number because I suspect they peform almost identically once in
> service. The one without the spring, however, is quite noisy as you have
> discovered.
>
> I've also come to believe that there is very little that breaks on a PCV
> valve that might require its replacement, short of a broken spring. What
> does happen is that they clog up and could use a good cleaning from time to
> time. A little blast of WD-40 followed by brake cleaner and they're good as
> new.
>
> Oh, and you can tell the ones without the spring before you buy them by
> shaking the package. The weight moves freely if there is no spring.
>
> My 2 cents.
01-30-2006 | 10:22 PM
#16
Guest
Posts: n/a
Re: PCV rattle 98 JGC 5.2
There's absolutely no way it would work without a spring to open
the valve at low open throttle vacuum!
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
RCSnyder wrote:
>
> There are actually two different PCV valve designs for the Mopar SB, one
> with and one without a spring. I've also found that they may carry the same
> part number because I suspect they peform almost identically once in
> service. The one without the spring, however, is quite noisy as you have
> discovered.
>
> I've also come to believe that there is very little that breaks on a PCV
> valve that might require its replacement, short of a broken spring. What
> does happen is that they clog up and could use a good cleaning from time to
> time. A little blast of WD-40 followed by brake cleaner and they're good as
> new.
>
> Oh, and you can tell the ones without the spring before you buy them by
> shaking the package. The weight moves freely if there is no spring.
>
> My 2 cents.
the valve at low open throttle vacuum!
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
RCSnyder wrote:
>
> There are actually two different PCV valve designs for the Mopar SB, one
> with and one without a spring. I've also found that they may carry the same
> part number because I suspect they peform almost identically once in
> service. The one without the spring, however, is quite noisy as you have
> discovered.
>
> I've also come to believe that there is very little that breaks on a PCV
> valve that might require its replacement, short of a broken spring. What
> does happen is that they clog up and could use a good cleaning from time to
> time. A little blast of WD-40 followed by brake cleaner and they're good as
> new.
>
> Oh, and you can tell the ones without the spring before you buy them by
> shaking the package. The weight moves freely if there is no spring.
>
> My 2 cents.
02-01-2006 | 10:24 PM
#17
Guest
Posts: n/a
Re: PCV rattle 98 JGC 5.2
Bill,
I must beg to differ.
I have purchased two very different replacement SB PCV valves wearing the
same Fram part number and the difference between them was one had a spring
and the other did not. The one without the spring rattles like a baby's toy
at idle while the one with the spring is hardly noticable. I tossed the
baby rattle for the same reason as did JRK58.
Fram apparently does not consider the presence of the spring as required for
proper operation of the PCV circuit in a Mopar SB, nor do based on my
understanding of the valve's operation.
For those who are unfamiliar with the related airflow process, I pulled this
from http://autorepair.about.com/library/faqs/bl102b.htm
"The theory behind PCV operation is this, A hose from the intake manifold
goes to the PCV valve. The PCV valve usually sits in the top of the valve
cover. Then another hose comes from the air filter housing, either from the
inside of the air filter or through a breather filter, and to the crankcase.
Now when the engine is running air is drawn from the air filter housing into
the crankcase, through the PCV and into the intake. So there is a vacuum
inside the crankcase."
It would appear that the rather upright orientation of the valve when
installed in a SB valve cover allows the valve weight to provide enough
closing pressure keep the air flowing the proper direction while maintain
the required amount of manifold vacuum. Contrary to your statement, the
spring's purpose is not to open the valve at low throttle but to keep it
closed until vacuum pulls it open so that a certain amount of manifold
vacuum is maintained at all times.
Think about the importance of maintaining manifold vacuum. Power brakes
would be without assist, vacuum spark advance curcuits would be neutered
along with many emission control systems. Fortunately PCV valves gum up
more often than stick open making their failure less noticable. Poor fuel
mileage and a black exhaust pipe would be good things to watch for in a more
modern engine.
Hope this helps.
Bob
"L.W. ("ßill") ------ III" <----------@***.net> wrote in message
news:43DED7ED.F5B50964@***.net...
> There's absolutely no way it would work without a spring to open
> the valve at low open throttle vacuum!
> God Bless America, Bill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> RCSnyder wrote:
>>
>> There are actually two different PCV valve designs for the Mopar SB, one
>> with and one without a spring. I've also found that they may carry the
>> same
>> part number because I suspect they peform almost identically once in
>> service. The one without the spring, however, is quite noisy as you have
>> discovered.
>>
>> I've also come to believe that there is very little that breaks on a PCV
>> valve that might require its replacement, short of a broken spring. What
>> does happen is that they clog up and could use a good cleaning from time
>> to
>> time. A little blast of WD-40 followed by brake cleaner and they're good
>> as
>> new.
>>
>> Oh, and you can tell the ones without the spring before you buy them by
>> shaking the package. The weight moves freely if there is no spring.
>>
>> My 2 cents.
I must beg to differ.
I have purchased two very different replacement SB PCV valves wearing the
same Fram part number and the difference between them was one had a spring
and the other did not. The one without the spring rattles like a baby's toy
at idle while the one with the spring is hardly noticable. I tossed the
baby rattle for the same reason as did JRK58.
Fram apparently does not consider the presence of the spring as required for
proper operation of the PCV circuit in a Mopar SB, nor do based on my
understanding of the valve's operation.
For those who are unfamiliar with the related airflow process, I pulled this
from http://autorepair.about.com/library/faqs/bl102b.htm
"The theory behind PCV operation is this, A hose from the intake manifold
goes to the PCV valve. The PCV valve usually sits in the top of the valve
cover. Then another hose comes from the air filter housing, either from the
inside of the air filter or through a breather filter, and to the crankcase.
Now when the engine is running air is drawn from the air filter housing into
the crankcase, through the PCV and into the intake. So there is a vacuum
inside the crankcase."
It would appear that the rather upright orientation of the valve when
installed in a SB valve cover allows the valve weight to provide enough
closing pressure keep the air flowing the proper direction while maintain
the required amount of manifold vacuum. Contrary to your statement, the
spring's purpose is not to open the valve at low throttle but to keep it
closed until vacuum pulls it open so that a certain amount of manifold
vacuum is maintained at all times.
Think about the importance of maintaining manifold vacuum. Power brakes
would be without assist, vacuum spark advance curcuits would be neutered
along with many emission control systems. Fortunately PCV valves gum up
more often than stick open making their failure less noticable. Poor fuel
mileage and a black exhaust pipe would be good things to watch for in a more
modern engine.
Hope this helps.
Bob
"L.W. ("ßill") ------ III" <----------@***.net> wrote in message
news:43DED7ED.F5B50964@***.net...
> There's absolutely no way it would work without a spring to open
> the valve at low open throttle vacuum!
> God Bless America, Bill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> RCSnyder wrote:
>>
>> There are actually two different PCV valve designs for the Mopar SB, one
>> with and one without a spring. I've also found that they may carry the
>> same
>> part number because I suspect they peform almost identically once in
>> service. The one without the spring, however, is quite noisy as you have
>> discovered.
>>
>> I've also come to believe that there is very little that breaks on a PCV
>> valve that might require its replacement, short of a broken spring. What
>> does happen is that they clog up and could use a good cleaning from time
>> to
>> time. A little blast of WD-40 followed by brake cleaner and they're good
>> as
>> new.
>>
>> Oh, and you can tell the ones without the spring before you buy them by
>> shaking the package. The weight moves freely if there is no spring.
>>
>> My 2 cents.
02-01-2006 | 10:24 PM
#18
Guest
Posts: n/a
Re: PCV rattle 98 JGC 5.2
Bill,
I must beg to differ.
I have purchased two very different replacement SB PCV valves wearing the
same Fram part number and the difference between them was one had a spring
and the other did not. The one without the spring rattles like a baby's toy
at idle while the one with the spring is hardly noticable. I tossed the
baby rattle for the same reason as did JRK58.
Fram apparently does not consider the presence of the spring as required for
proper operation of the PCV circuit in a Mopar SB, nor do based on my
understanding of the valve's operation.
For those who are unfamiliar with the related airflow process, I pulled this
from http://autorepair.about.com/library/faqs/bl102b.htm
"The theory behind PCV operation is this, A hose from the intake manifold
goes to the PCV valve. The PCV valve usually sits in the top of the valve
cover. Then another hose comes from the air filter housing, either from the
inside of the air filter or through a breather filter, and to the crankcase.
Now when the engine is running air is drawn from the air filter housing into
the crankcase, through the PCV and into the intake. So there is a vacuum
inside the crankcase."
It would appear that the rather upright orientation of the valve when
installed in a SB valve cover allows the valve weight to provide enough
closing pressure keep the air flowing the proper direction while maintain
the required amount of manifold vacuum. Contrary to your statement, the
spring's purpose is not to open the valve at low throttle but to keep it
closed until vacuum pulls it open so that a certain amount of manifold
vacuum is maintained at all times.
Think about the importance of maintaining manifold vacuum. Power brakes
would be without assist, vacuum spark advance curcuits would be neutered
along with many emission control systems. Fortunately PCV valves gum up
more often than stick open making their failure less noticable. Poor fuel
mileage and a black exhaust pipe would be good things to watch for in a more
modern engine.
Hope this helps.
Bob
"L.W. ("ßill") ------ III" <----------@***.net> wrote in message
news:43DED7ED.F5B50964@***.net...
> There's absolutely no way it would work without a spring to open
> the valve at low open throttle vacuum!
> God Bless America, Bill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> RCSnyder wrote:
>>
>> There are actually two different PCV valve designs for the Mopar SB, one
>> with and one without a spring. I've also found that they may carry the
>> same
>> part number because I suspect they peform almost identically once in
>> service. The one without the spring, however, is quite noisy as you have
>> discovered.
>>
>> I've also come to believe that there is very little that breaks on a PCV
>> valve that might require its replacement, short of a broken spring. What
>> does happen is that they clog up and could use a good cleaning from time
>> to
>> time. A little blast of WD-40 followed by brake cleaner and they're good
>> as
>> new.
>>
>> Oh, and you can tell the ones without the spring before you buy them by
>> shaking the package. The weight moves freely if there is no spring.
>>
>> My 2 cents.
I must beg to differ.
I have purchased two very different replacement SB PCV valves wearing the
same Fram part number and the difference between them was one had a spring
and the other did not. The one without the spring rattles like a baby's toy
at idle while the one with the spring is hardly noticable. I tossed the
baby rattle for the same reason as did JRK58.
Fram apparently does not consider the presence of the spring as required for
proper operation of the PCV circuit in a Mopar SB, nor do based on my
understanding of the valve's operation.
For those who are unfamiliar with the related airflow process, I pulled this
from http://autorepair.about.com/library/faqs/bl102b.htm
"The theory behind PCV operation is this, A hose from the intake manifold
goes to the PCV valve. The PCV valve usually sits in the top of the valve
cover. Then another hose comes from the air filter housing, either from the
inside of the air filter or through a breather filter, and to the crankcase.
Now when the engine is running air is drawn from the air filter housing into
the crankcase, through the PCV and into the intake. So there is a vacuum
inside the crankcase."
It would appear that the rather upright orientation of the valve when
installed in a SB valve cover allows the valve weight to provide enough
closing pressure keep the air flowing the proper direction while maintain
the required amount of manifold vacuum. Contrary to your statement, the
spring's purpose is not to open the valve at low throttle but to keep it
closed until vacuum pulls it open so that a certain amount of manifold
vacuum is maintained at all times.
Think about the importance of maintaining manifold vacuum. Power brakes
would be without assist, vacuum spark advance curcuits would be neutered
along with many emission control systems. Fortunately PCV valves gum up
more often than stick open making their failure less noticable. Poor fuel
mileage and a black exhaust pipe would be good things to watch for in a more
modern engine.
Hope this helps.
Bob
"L.W. ("ßill") ------ III" <----------@***.net> wrote in message
news:43DED7ED.F5B50964@***.net...
> There's absolutely no way it would work without a spring to open
> the valve at low open throttle vacuum!
> God Bless America, Bill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> RCSnyder wrote:
>>
>> There are actually two different PCV valve designs for the Mopar SB, one
>> with and one without a spring. I've also found that they may carry the
>> same
>> part number because I suspect they peform almost identically once in
>> service. The one without the spring, however, is quite noisy as you have
>> discovered.
>>
>> I've also come to believe that there is very little that breaks on a PCV
>> valve that might require its replacement, short of a broken spring. What
>> does happen is that they clog up and could use a good cleaning from time
>> to
>> time. A little blast of WD-40 followed by brake cleaner and they're good
>> as
>> new.
>>
>> Oh, and you can tell the ones without the spring before you buy them by
>> shaking the package. The weight moves freely if there is no spring.
>>
>> My 2 cents.
02-01-2006 | 10:24 PM
#19
Guest
Posts: n/a
Re: PCV rattle 98 JGC 5.2
Bill,
I must beg to differ.
I have purchased two very different replacement SB PCV valves wearing the
same Fram part number and the difference between them was one had a spring
and the other did not. The one without the spring rattles like a baby's toy
at idle while the one with the spring is hardly noticable. I tossed the
baby rattle for the same reason as did JRK58.
Fram apparently does not consider the presence of the spring as required for
proper operation of the PCV circuit in a Mopar SB, nor do based on my
understanding of the valve's operation.
For those who are unfamiliar with the related airflow process, I pulled this
from http://autorepair.about.com/library/faqs/bl102b.htm
"The theory behind PCV operation is this, A hose from the intake manifold
goes to the PCV valve. The PCV valve usually sits in the top of the valve
cover. Then another hose comes from the air filter housing, either from the
inside of the air filter or through a breather filter, and to the crankcase.
Now when the engine is running air is drawn from the air filter housing into
the crankcase, through the PCV and into the intake. So there is a vacuum
inside the crankcase."
It would appear that the rather upright orientation of the valve when
installed in a SB valve cover allows the valve weight to provide enough
closing pressure keep the air flowing the proper direction while maintain
the required amount of manifold vacuum. Contrary to your statement, the
spring's purpose is not to open the valve at low throttle but to keep it
closed until vacuum pulls it open so that a certain amount of manifold
vacuum is maintained at all times.
Think about the importance of maintaining manifold vacuum. Power brakes
would be without assist, vacuum spark advance curcuits would be neutered
along with many emission control systems. Fortunately PCV valves gum up
more often than stick open making their failure less noticable. Poor fuel
mileage and a black exhaust pipe would be good things to watch for in a more
modern engine.
Hope this helps.
Bob
"L.W. ("ßill") ------ III" <----------@***.net> wrote in message
news:43DED7ED.F5B50964@***.net...
> There's absolutely no way it would work without a spring to open
> the valve at low open throttle vacuum!
> God Bless America, Bill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> RCSnyder wrote:
>>
>> There are actually two different PCV valve designs for the Mopar SB, one
>> with and one without a spring. I've also found that they may carry the
>> same
>> part number because I suspect they peform almost identically once in
>> service. The one without the spring, however, is quite noisy as you have
>> discovered.
>>
>> I've also come to believe that there is very little that breaks on a PCV
>> valve that might require its replacement, short of a broken spring. What
>> does happen is that they clog up and could use a good cleaning from time
>> to
>> time. A little blast of WD-40 followed by brake cleaner and they're good
>> as
>> new.
>>
>> Oh, and you can tell the ones without the spring before you buy them by
>> shaking the package. The weight moves freely if there is no spring.
>>
>> My 2 cents.
I must beg to differ.
I have purchased two very different replacement SB PCV valves wearing the
same Fram part number and the difference between them was one had a spring
and the other did not. The one without the spring rattles like a baby's toy
at idle while the one with the spring is hardly noticable. I tossed the
baby rattle for the same reason as did JRK58.
Fram apparently does not consider the presence of the spring as required for
proper operation of the PCV circuit in a Mopar SB, nor do based on my
understanding of the valve's operation.
For those who are unfamiliar with the related airflow process, I pulled this
from http://autorepair.about.com/library/faqs/bl102b.htm
"The theory behind PCV operation is this, A hose from the intake manifold
goes to the PCV valve. The PCV valve usually sits in the top of the valve
cover. Then another hose comes from the air filter housing, either from the
inside of the air filter or through a breather filter, and to the crankcase.
Now when the engine is running air is drawn from the air filter housing into
the crankcase, through the PCV and into the intake. So there is a vacuum
inside the crankcase."
It would appear that the rather upright orientation of the valve when
installed in a SB valve cover allows the valve weight to provide enough
closing pressure keep the air flowing the proper direction while maintain
the required amount of manifold vacuum. Contrary to your statement, the
spring's purpose is not to open the valve at low throttle but to keep it
closed until vacuum pulls it open so that a certain amount of manifold
vacuum is maintained at all times.
Think about the importance of maintaining manifold vacuum. Power brakes
would be without assist, vacuum spark advance curcuits would be neutered
along with many emission control systems. Fortunately PCV valves gum up
more often than stick open making their failure less noticable. Poor fuel
mileage and a black exhaust pipe would be good things to watch for in a more
modern engine.
Hope this helps.
Bob
"L.W. ("ßill") ------ III" <----------@***.net> wrote in message
news:43DED7ED.F5B50964@***.net...
> There's absolutely no way it would work without a spring to open
> the valve at low open throttle vacuum!
> God Bless America, Bill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> RCSnyder wrote:
>>
>> There are actually two different PCV valve designs for the Mopar SB, one
>> with and one without a spring. I've also found that they may carry the
>> same
>> part number because I suspect they peform almost identically once in
>> service. The one without the spring, however, is quite noisy as you have
>> discovered.
>>
>> I've also come to believe that there is very little that breaks on a PCV
>> valve that might require its replacement, short of a broken spring. What
>> does happen is that they clog up and could use a good cleaning from time
>> to
>> time. A little blast of WD-40 followed by brake cleaner and they're good
>> as
>> new.
>>
>> Oh, and you can tell the ones without the spring before you buy them by
>> shaking the package. The weight moves freely if there is no spring.
>>
>> My 2 cents.
02-01-2006 | 10:52 PM
#20
Guest
Posts: n/a
Re: PCV rattle 98 JGC 5.2
I have no idea what would push the PCV piston back off the seat
without a spring strong enough to open it a against low vacuum:
http://members.rennlist.com/pbanders/PCV.htm
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
RCSnyder wrote:
>
> Bill,
>
> I must beg to differ.
>
> I have purchased two very different replacement SB PCV valves wearing the
> same Fram part number and the difference between them was one had a spring
> and the other did not. The one without the spring rattles like a baby's toy
> at idle while the one with the spring is hardly noticable. I tossed the
> baby rattle for the same reason as did JRK58.
>
> Fram apparently does not consider the presence of the spring as required for
> proper operation of the PCV circuit in a Mopar SB, nor do based on my
> understanding of the valve's operation.
>
> For those who are unfamiliar with the related airflow process, I pulled this
> from http://autorepair.about.com/library/faqs/bl102b.htm
>
> "The theory behind PCV operation is this, A hose from the intake manifold
> goes to the PCV valve. The PCV valve usually sits in the top of the valve
> cover. Then another hose comes from the air filter housing, either from the
> inside of the air filter or through a breather filter, and to the crankcase.
> Now when the engine is running air is drawn from the air filter housing into
> the crankcase, through the PCV and into the intake. So there is a vacuum
> inside the crankcase."
>
> It would appear that the rather upright orientation of the valve when
> installed in a SB valve cover allows the valve weight to provide enough
> closing pressure keep the air flowing the proper direction while maintain
> the required amount of manifold vacuum. Contrary to your statement, the
> spring's purpose is not to open the valve at low throttle but to keep it
> closed until vacuum pulls it open so that a certain amount of manifold
> vacuum is maintained at all times.
>
> Think about the importance of maintaining manifold vacuum. Power brakes
> would be without assist, vacuum spark advance curcuits would be neutered
> along with many emission control systems. Fortunately PCV valves gum up
> more often than stick open making their failure less noticable. Poor fuel
> mileage and a black exhaust pipe would be good things to watch for in a more
> modern engine.
>
> Hope this helps.
>
> Bob
without a spring strong enough to open it a against low vacuum:
http://members.rennlist.com/pbanders/PCV.htm
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
RCSnyder wrote:
>
> Bill,
>
> I must beg to differ.
>
> I have purchased two very different replacement SB PCV valves wearing the
> same Fram part number and the difference between them was one had a spring
> and the other did not. The one without the spring rattles like a baby's toy
> at idle while the one with the spring is hardly noticable. I tossed the
> baby rattle for the same reason as did JRK58.
>
> Fram apparently does not consider the presence of the spring as required for
> proper operation of the PCV circuit in a Mopar SB, nor do based on my
> understanding of the valve's operation.
>
> For those who are unfamiliar with the related airflow process, I pulled this
> from http://autorepair.about.com/library/faqs/bl102b.htm
>
> "The theory behind PCV operation is this, A hose from the intake manifold
> goes to the PCV valve. The PCV valve usually sits in the top of the valve
> cover. Then another hose comes from the air filter housing, either from the
> inside of the air filter or through a breather filter, and to the crankcase.
> Now when the engine is running air is drawn from the air filter housing into
> the crankcase, through the PCV and into the intake. So there is a vacuum
> inside the crankcase."
>
> It would appear that the rather upright orientation of the valve when
> installed in a SB valve cover allows the valve weight to provide enough
> closing pressure keep the air flowing the proper direction while maintain
> the required amount of manifold vacuum. Contrary to your statement, the
> spring's purpose is not to open the valve at low throttle but to keep it
> closed until vacuum pulls it open so that a certain amount of manifold
> vacuum is maintained at all times.
>
> Think about the importance of maintaining manifold vacuum. Power brakes
> would be without assist, vacuum spark advance curcuits would be neutered
> along with many emission control systems. Fortunately PCV valves gum up
> more often than stick open making their failure less noticable. Poor fuel
> mileage and a black exhaust pipe would be good things to watch for in a more
> modern engine.
>
> Hope this helps.
>
> Bob