How does low oil pressure indicate bad bearings?
#11
Guest
Posts: n/a
Re: How does low oil pressure indicate bad bearings?
hmmmmmmm...........................similar situation with your blood
pressure
--
Carlo F. Serusa, Jr. RPh
carlo.jr at comcast DOTnet
'98 Sahara TJ - '89 YJ - '79 Scout II
O|||||||O
'92 Explorer '65 Mustang
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4048DD79.829D4BF1@sympatico.ca...
> Oil pumps have to have resistance to build up pressure or the oil just
> flows free at 0 psi.
>
> The oil channels lead to the bearings have a 'little' restriction, but
> not much. The big restriction is at the bearing faces.
>
> The biggest bearings are on the crank so when the bearing faces get
> worn, the restriction goes away and the oil flows past faster and under
> lower psi.
>
> This makes for a lower pressure reading on a gauge in the system.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Mike mentioned this in another post and it's not coming through my
little
> > pea brain how that works. How does worn bearings produce low oil
pressure?
> > What's the relation?
> >
> > Thanks,
> >
> > Billo
pressure
--
Carlo F. Serusa, Jr. RPh
carlo.jr at comcast DOTnet
'98 Sahara TJ - '89 YJ - '79 Scout II
O|||||||O
'92 Explorer '65 Mustang
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4048DD79.829D4BF1@sympatico.ca...
> Oil pumps have to have resistance to build up pressure or the oil just
> flows free at 0 psi.
>
> The oil channels lead to the bearings have a 'little' restriction, but
> not much. The big restriction is at the bearing faces.
>
> The biggest bearings are on the crank so when the bearing faces get
> worn, the restriction goes away and the oil flows past faster and under
> lower psi.
>
> This makes for a lower pressure reading on a gauge in the system.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Mike mentioned this in another post and it's not coming through my
little
> > pea brain how that works. How does worn bearings produce low oil
pressure?
> > What's the relation?
> >
> > Thanks,
> >
> > Billo
#12
Guest
Posts: n/a
Re: How does low oil pressure indicate bad bearings?
hmmmmmmm...........................similar situation with your blood
pressure
--
Carlo F. Serusa, Jr. RPh
carlo.jr at comcast DOTnet
'98 Sahara TJ - '89 YJ - '79 Scout II
O|||||||O
'92 Explorer '65 Mustang
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4048DD79.829D4BF1@sympatico.ca...
> Oil pumps have to have resistance to build up pressure or the oil just
> flows free at 0 psi.
>
> The oil channels lead to the bearings have a 'little' restriction, but
> not much. The big restriction is at the bearing faces.
>
> The biggest bearings are on the crank so when the bearing faces get
> worn, the restriction goes away and the oil flows past faster and under
> lower psi.
>
> This makes for a lower pressure reading on a gauge in the system.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Mike mentioned this in another post and it's not coming through my
little
> > pea brain how that works. How does worn bearings produce low oil
pressure?
> > What's the relation?
> >
> > Thanks,
> >
> > Billo
pressure
--
Carlo F. Serusa, Jr. RPh
carlo.jr at comcast DOTnet
'98 Sahara TJ - '89 YJ - '79 Scout II
O|||||||O
'92 Explorer '65 Mustang
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4048DD79.829D4BF1@sympatico.ca...
> Oil pumps have to have resistance to build up pressure or the oil just
> flows free at 0 psi.
>
> The oil channels lead to the bearings have a 'little' restriction, but
> not much. The big restriction is at the bearing faces.
>
> The biggest bearings are on the crank so when the bearing faces get
> worn, the restriction goes away and the oil flows past faster and under
> lower psi.
>
> This makes for a lower pressure reading on a gauge in the system.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Mike mentioned this in another post and it's not coming through my
little
> > pea brain how that works. How does worn bearings produce low oil
pressure?
> > What's the relation?
> >
> > Thanks,
> >
> > Billo
#13
Guest
Posts: n/a
Re: How does low oil pressure indicate bad bearings?
hmmmmmmm...........................similar situation with your blood
pressure
--
Carlo F. Serusa, Jr. RPh
carlo.jr at comcast DOTnet
'98 Sahara TJ - '89 YJ - '79 Scout II
O|||||||O
'92 Explorer '65 Mustang
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4048DD79.829D4BF1@sympatico.ca...
> Oil pumps have to have resistance to build up pressure or the oil just
> flows free at 0 psi.
>
> The oil channels lead to the bearings have a 'little' restriction, but
> not much. The big restriction is at the bearing faces.
>
> The biggest bearings are on the crank so when the bearing faces get
> worn, the restriction goes away and the oil flows past faster and under
> lower psi.
>
> This makes for a lower pressure reading on a gauge in the system.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Mike mentioned this in another post and it's not coming through my
little
> > pea brain how that works. How does worn bearings produce low oil
pressure?
> > What's the relation?
> >
> > Thanks,
> >
> > Billo
pressure
--
Carlo F. Serusa, Jr. RPh
carlo.jr at comcast DOTnet
'98 Sahara TJ - '89 YJ - '79 Scout II
O|||||||O
'92 Explorer '65 Mustang
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4048DD79.829D4BF1@sympatico.ca...
> Oil pumps have to have resistance to build up pressure or the oil just
> flows free at 0 psi.
>
> The oil channels lead to the bearings have a 'little' restriction, but
> not much. The big restriction is at the bearing faces.
>
> The biggest bearings are on the crank so when the bearing faces get
> worn, the restriction goes away and the oil flows past faster and under
> lower psi.
>
> This makes for a lower pressure reading on a gauge in the system.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Mike mentioned this in another post and it's not coming through my
little
> > pea brain how that works. How does worn bearings produce low oil
pressure?
> > What's the relation?
> >
> > Thanks,
> >
> > Billo
#14
Guest
Posts: n/a
Re: How does low oil pressure indicate bad bearings?
But you can't lower your blood pressure by poking a hole in an artery!!
makes sense to an irishman....but makes a mess too!
sb
"Carlo" <carlo.jr@comcast.net> wrote in message
news:XL6dnWh8PdHoztTdRVn-ig@comcast.com...
> hmmmmmmm...........................similar situation with your blood
> pressure
>
> --
> Carlo F. Serusa, Jr. RPh
> carlo.jr at comcast DOTnet
> '98 Sahara TJ - '89 YJ - '79 Scout II
> O|||||||O
> '92 Explorer '65 Mustang
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4048DD79.829D4BF1@sympatico.ca...
> > Oil pumps have to have resistance to build up pressure or the oil just
> > flows free at 0 psi.
> >
> > The oil channels lead to the bearings have a 'little' restriction, but
> > not much. The big restriction is at the bearing faces.
> >
> > The biggest bearings are on the crank so when the bearing faces get
> > worn, the restriction goes away and the oil flows past faster and under
> > lower psi.
> >
> > This makes for a lower pressure reading on a gauge in the system.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > William Oliveri wrote:
> > >
> > > Mike mentioned this in another post and it's not coming through my
> little
> > > pea brain how that works. How does worn bearings produce low oil
> pressure?
> > > What's the relation?
> > >
> > > Thanks,
> > >
> > > Billo
>
>
makes sense to an irishman....but makes a mess too!
sb
"Carlo" <carlo.jr@comcast.net> wrote in message
news:XL6dnWh8PdHoztTdRVn-ig@comcast.com...
> hmmmmmmm...........................similar situation with your blood
> pressure
>
> --
> Carlo F. Serusa, Jr. RPh
> carlo.jr at comcast DOTnet
> '98 Sahara TJ - '89 YJ - '79 Scout II
> O|||||||O
> '92 Explorer '65 Mustang
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4048DD79.829D4BF1@sympatico.ca...
> > Oil pumps have to have resistance to build up pressure or the oil just
> > flows free at 0 psi.
> >
> > The oil channels lead to the bearings have a 'little' restriction, but
> > not much. The big restriction is at the bearing faces.
> >
> > The biggest bearings are on the crank so when the bearing faces get
> > worn, the restriction goes away and the oil flows past faster and under
> > lower psi.
> >
> > This makes for a lower pressure reading on a gauge in the system.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > William Oliveri wrote:
> > >
> > > Mike mentioned this in another post and it's not coming through my
> little
> > > pea brain how that works. How does worn bearings produce low oil
> pressure?
> > > What's the relation?
> > >
> > > Thanks,
> > >
> > > Billo
>
>
#15
Guest
Posts: n/a
Re: How does low oil pressure indicate bad bearings?
But you can't lower your blood pressure by poking a hole in an artery!!
makes sense to an irishman....but makes a mess too!
sb
"Carlo" <carlo.jr@comcast.net> wrote in message
news:XL6dnWh8PdHoztTdRVn-ig@comcast.com...
> hmmmmmmm...........................similar situation with your blood
> pressure
>
> --
> Carlo F. Serusa, Jr. RPh
> carlo.jr at comcast DOTnet
> '98 Sahara TJ - '89 YJ - '79 Scout II
> O|||||||O
> '92 Explorer '65 Mustang
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4048DD79.829D4BF1@sympatico.ca...
> > Oil pumps have to have resistance to build up pressure or the oil just
> > flows free at 0 psi.
> >
> > The oil channels lead to the bearings have a 'little' restriction, but
> > not much. The big restriction is at the bearing faces.
> >
> > The biggest bearings are on the crank so when the bearing faces get
> > worn, the restriction goes away and the oil flows past faster and under
> > lower psi.
> >
> > This makes for a lower pressure reading on a gauge in the system.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > William Oliveri wrote:
> > >
> > > Mike mentioned this in another post and it's not coming through my
> little
> > > pea brain how that works. How does worn bearings produce low oil
> pressure?
> > > What's the relation?
> > >
> > > Thanks,
> > >
> > > Billo
>
>
makes sense to an irishman....but makes a mess too!
sb
"Carlo" <carlo.jr@comcast.net> wrote in message
news:XL6dnWh8PdHoztTdRVn-ig@comcast.com...
> hmmmmmmm...........................similar situation with your blood
> pressure
>
> --
> Carlo F. Serusa, Jr. RPh
> carlo.jr at comcast DOTnet
> '98 Sahara TJ - '89 YJ - '79 Scout II
> O|||||||O
> '92 Explorer '65 Mustang
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4048DD79.829D4BF1@sympatico.ca...
> > Oil pumps have to have resistance to build up pressure or the oil just
> > flows free at 0 psi.
> >
> > The oil channels lead to the bearings have a 'little' restriction, but
> > not much. The big restriction is at the bearing faces.
> >
> > The biggest bearings are on the crank so when the bearing faces get
> > worn, the restriction goes away and the oil flows past faster and under
> > lower psi.
> >
> > This makes for a lower pressure reading on a gauge in the system.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > William Oliveri wrote:
> > >
> > > Mike mentioned this in another post and it's not coming through my
> little
> > > pea brain how that works. How does worn bearings produce low oil
> pressure?
> > > What's the relation?
> > >
> > > Thanks,
> > >
> > > Billo
>
>
#16
Guest
Posts: n/a
Re: How does low oil pressure indicate bad bearings?
But you can't lower your blood pressure by poking a hole in an artery!!
makes sense to an irishman....but makes a mess too!
sb
"Carlo" <carlo.jr@comcast.net> wrote in message
news:XL6dnWh8PdHoztTdRVn-ig@comcast.com...
> hmmmmmmm...........................similar situation with your blood
> pressure
>
> --
> Carlo F. Serusa, Jr. RPh
> carlo.jr at comcast DOTnet
> '98 Sahara TJ - '89 YJ - '79 Scout II
> O|||||||O
> '92 Explorer '65 Mustang
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4048DD79.829D4BF1@sympatico.ca...
> > Oil pumps have to have resistance to build up pressure or the oil just
> > flows free at 0 psi.
> >
> > The oil channels lead to the bearings have a 'little' restriction, but
> > not much. The big restriction is at the bearing faces.
> >
> > The biggest bearings are on the crank so when the bearing faces get
> > worn, the restriction goes away and the oil flows past faster and under
> > lower psi.
> >
> > This makes for a lower pressure reading on a gauge in the system.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > William Oliveri wrote:
> > >
> > > Mike mentioned this in another post and it's not coming through my
> little
> > > pea brain how that works. How does worn bearings produce low oil
> pressure?
> > > What's the relation?
> > >
> > > Thanks,
> > >
> > > Billo
>
>
makes sense to an irishman....but makes a mess too!
sb
"Carlo" <carlo.jr@comcast.net> wrote in message
news:XL6dnWh8PdHoztTdRVn-ig@comcast.com...
> hmmmmmmm...........................similar situation with your blood
> pressure
>
> --
> Carlo F. Serusa, Jr. RPh
> carlo.jr at comcast DOTnet
> '98 Sahara TJ - '89 YJ - '79 Scout II
> O|||||||O
> '92 Explorer '65 Mustang
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4048DD79.829D4BF1@sympatico.ca...
> > Oil pumps have to have resistance to build up pressure or the oil just
> > flows free at 0 psi.
> >
> > The oil channels lead to the bearings have a 'little' restriction, but
> > not much. The big restriction is at the bearing faces.
> >
> > The biggest bearings are on the crank so when the bearing faces get
> > worn, the restriction goes away and the oil flows past faster and under
> > lower psi.
> >
> > This makes for a lower pressure reading on a gauge in the system.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > William Oliveri wrote:
> > >
> > > Mike mentioned this in another post and it's not coming through my
> little
> > > pea brain how that works. How does worn bearings produce low oil
> pressure?
> > > What's the relation?
> > >
> > > Thanks,
> > >
> > > Billo
>
>
#17
Guest
Posts: n/a
Re: How does low oil pressure indicate bad bearings?
Yes, the oil pressure will get slowly lower over time as parts wear.
There is a minimum safe pressure. Once that is reached, wear starts
happening fast.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Joseph P wrote:
>
> So, in my 98 TJ, my oil pressure at idle is pretty low compared to
> what it used to be (I think). It seems to be down around 30psi at
> idle, but at speed it is up around 50 or so. Is this the type of
> indicator we are talking about for worn crank bearings, assuming of
> course my pump and pressure sending unit are good. It only has 66k
> miles on it (around there, would have to double check.)
>
> --
> --
> Joe Pribe
> NC
> jpribe 'at' nc.rr.com <you know the drill
> jegp 'at' hotmail.com < at is really @
> ---- I Love My O|||||||O TJ
>
> "CRWLR" <beerman@yahoo.com> wrote in message
> news:104hrntpkjur30b@corp.supernews.com...
> | Think of the sprinklers out in your yard.
> |
> | There is probably about 10 of them connected to a single valve, and
> you have
> | perhaps 6 valves to water the front and rear lawns, and the planter
> boxes.
> | There is something like 60 psi on the system, and if there are too
> many
> | sprinkler heads on a single line, then none of the sprinklers will
> spray
> | very well because the pressure at any one head will drop relative to
> the
> | pressure there would be if there were fewer heads. If one head blows
> off,
> | then the water flow through the remaining heads will drop.
> |
> | Your bearings are kinda similar. There are a number of particular
> sized
> | holes (gallies) that the oil will flow through. If a bearing wears,
> then the
> | oil pressure will drop because the amount of oil that can flow there
> will
> | increase. If the crank and bearings are in good shape, then the oil
> galley
> | is a known size. but, if the bearing or crank journal wears, then
> the galley
> | effectively becomes larger because oil can not fit in the space
> between the
> | crank and the bearing face. When this happens, there is less oil for
> some
> | location further down the line. Basically, the oil pressure is
> dependent
> | upon having specific sizes of oriffices to be pushed through, if one
> or more
> | of those oriffices can accomodate more oil that it is designed to,
> then the
> | remaining oriffices will get less oil because the amount of oil
> available is
> | fixed due to the capacity of the oil pump.
> |
> | If the bearings wore a little bit, then theoritically one could
> install a
> | higher capacity pump to raise the amount of oil available. the
> problem with
> | that theory is that the worn parts will continue to wear, requiring
> | increasingly larger capacity pumps. At some point, the ability of
> the pump
> | to do its job would exceed the ability of the oil passages to carry
> oil, and
> | the pump would cavatate, and you would still have the worn bearings
> that
> | allowed the oil to bypass all of the other places that it ought to
> be going.
> | If you connected a fire hose to your sprinkler system that had lost
> a head,
> | the other heads might get some water, but the one that was broken
> would
> | still be broken and lots of water would be wasted. (there is a
> significant
> | difference in the oil pump and the fire hose, the pump is in a
> closed system
> | so there wouldn't be the waste, but what these have in common is
> that there
> | would be lots of oil in a place that couldn't benefit from it, and
> minimal
> | oil in a place that needs it badly.)
> |
> |
> |
> |
> |
> | "William Oliveri" <wuji@bigvalley.net> wrote in message
> | news:c2am04$1qphp5$1@ID-193866.news.uni-berlin.de...
> | > Mike mentioned this in another post and it's not coming through my
> little
> | > pea brain how that works. How does worn bearings produce low oil
> | pressure?
> | > What's the relation?
> | >
> | >
> | > Thanks,
> | >
> | > Billo
> | >
> | >
> |
There is a minimum safe pressure. Once that is reached, wear starts
happening fast.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Joseph P wrote:
>
> So, in my 98 TJ, my oil pressure at idle is pretty low compared to
> what it used to be (I think). It seems to be down around 30psi at
> idle, but at speed it is up around 50 or so. Is this the type of
> indicator we are talking about for worn crank bearings, assuming of
> course my pump and pressure sending unit are good. It only has 66k
> miles on it (around there, would have to double check.)
>
> --
> --
> Joe Pribe
> NC
> jpribe 'at' nc.rr.com <you know the drill
> jegp 'at' hotmail.com < at is really @
> ---- I Love My O|||||||O TJ
>
> "CRWLR" <beerman@yahoo.com> wrote in message
> news:104hrntpkjur30b@corp.supernews.com...
> | Think of the sprinklers out in your yard.
> |
> | There is probably about 10 of them connected to a single valve, and
> you have
> | perhaps 6 valves to water the front and rear lawns, and the planter
> boxes.
> | There is something like 60 psi on the system, and if there are too
> many
> | sprinkler heads on a single line, then none of the sprinklers will
> spray
> | very well because the pressure at any one head will drop relative to
> the
> | pressure there would be if there were fewer heads. If one head blows
> off,
> | then the water flow through the remaining heads will drop.
> |
> | Your bearings are kinda similar. There are a number of particular
> sized
> | holes (gallies) that the oil will flow through. If a bearing wears,
> then the
> | oil pressure will drop because the amount of oil that can flow there
> will
> | increase. If the crank and bearings are in good shape, then the oil
> galley
> | is a known size. but, if the bearing or crank journal wears, then
> the galley
> | effectively becomes larger because oil can not fit in the space
> between the
> | crank and the bearing face. When this happens, there is less oil for
> some
> | location further down the line. Basically, the oil pressure is
> dependent
> | upon having specific sizes of oriffices to be pushed through, if one
> or more
> | of those oriffices can accomodate more oil that it is designed to,
> then the
> | remaining oriffices will get less oil because the amount of oil
> available is
> | fixed due to the capacity of the oil pump.
> |
> | If the bearings wore a little bit, then theoritically one could
> install a
> | higher capacity pump to raise the amount of oil available. the
> problem with
> | that theory is that the worn parts will continue to wear, requiring
> | increasingly larger capacity pumps. At some point, the ability of
> the pump
> | to do its job would exceed the ability of the oil passages to carry
> oil, and
> | the pump would cavatate, and you would still have the worn bearings
> that
> | allowed the oil to bypass all of the other places that it ought to
> be going.
> | If you connected a fire hose to your sprinkler system that had lost
> a head,
> | the other heads might get some water, but the one that was broken
> would
> | still be broken and lots of water would be wasted. (there is a
> significant
> | difference in the oil pump and the fire hose, the pump is in a
> closed system
> | so there wouldn't be the waste, but what these have in common is
> that there
> | would be lots of oil in a place that couldn't benefit from it, and
> minimal
> | oil in a place that needs it badly.)
> |
> |
> |
> |
> |
> | "William Oliveri" <wuji@bigvalley.net> wrote in message
> | news:c2am04$1qphp5$1@ID-193866.news.uni-berlin.de...
> | > Mike mentioned this in another post and it's not coming through my
> little
> | > pea brain how that works. How does worn bearings produce low oil
> | pressure?
> | > What's the relation?
> | >
> | >
> | > Thanks,
> | >
> | > Billo
> | >
> | >
> |
#18
Guest
Posts: n/a
Re: How does low oil pressure indicate bad bearings?
Yes, the oil pressure will get slowly lower over time as parts wear.
There is a minimum safe pressure. Once that is reached, wear starts
happening fast.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Joseph P wrote:
>
> So, in my 98 TJ, my oil pressure at idle is pretty low compared to
> what it used to be (I think). It seems to be down around 30psi at
> idle, but at speed it is up around 50 or so. Is this the type of
> indicator we are talking about for worn crank bearings, assuming of
> course my pump and pressure sending unit are good. It only has 66k
> miles on it (around there, would have to double check.)
>
> --
> --
> Joe Pribe
> NC
> jpribe 'at' nc.rr.com <you know the drill
> jegp 'at' hotmail.com < at is really @
> ---- I Love My O|||||||O TJ
>
> "CRWLR" <beerman@yahoo.com> wrote in message
> news:104hrntpkjur30b@corp.supernews.com...
> | Think of the sprinklers out in your yard.
> |
> | There is probably about 10 of them connected to a single valve, and
> you have
> | perhaps 6 valves to water the front and rear lawns, and the planter
> boxes.
> | There is something like 60 psi on the system, and if there are too
> many
> | sprinkler heads on a single line, then none of the sprinklers will
> spray
> | very well because the pressure at any one head will drop relative to
> the
> | pressure there would be if there were fewer heads. If one head blows
> off,
> | then the water flow through the remaining heads will drop.
> |
> | Your bearings are kinda similar. There are a number of particular
> sized
> | holes (gallies) that the oil will flow through. If a bearing wears,
> then the
> | oil pressure will drop because the amount of oil that can flow there
> will
> | increase. If the crank and bearings are in good shape, then the oil
> galley
> | is a known size. but, if the bearing or crank journal wears, then
> the galley
> | effectively becomes larger because oil can not fit in the space
> between the
> | crank and the bearing face. When this happens, there is less oil for
> some
> | location further down the line. Basically, the oil pressure is
> dependent
> | upon having specific sizes of oriffices to be pushed through, if one
> or more
> | of those oriffices can accomodate more oil that it is designed to,
> then the
> | remaining oriffices will get less oil because the amount of oil
> available is
> | fixed due to the capacity of the oil pump.
> |
> | If the bearings wore a little bit, then theoritically one could
> install a
> | higher capacity pump to raise the amount of oil available. the
> problem with
> | that theory is that the worn parts will continue to wear, requiring
> | increasingly larger capacity pumps. At some point, the ability of
> the pump
> | to do its job would exceed the ability of the oil passages to carry
> oil, and
> | the pump would cavatate, and you would still have the worn bearings
> that
> | allowed the oil to bypass all of the other places that it ought to
> be going.
> | If you connected a fire hose to your sprinkler system that had lost
> a head,
> | the other heads might get some water, but the one that was broken
> would
> | still be broken and lots of water would be wasted. (there is a
> significant
> | difference in the oil pump and the fire hose, the pump is in a
> closed system
> | so there wouldn't be the waste, but what these have in common is
> that there
> | would be lots of oil in a place that couldn't benefit from it, and
> minimal
> | oil in a place that needs it badly.)
> |
> |
> |
> |
> |
> | "William Oliveri" <wuji@bigvalley.net> wrote in message
> | news:c2am04$1qphp5$1@ID-193866.news.uni-berlin.de...
> | > Mike mentioned this in another post and it's not coming through my
> little
> | > pea brain how that works. How does worn bearings produce low oil
> | pressure?
> | > What's the relation?
> | >
> | >
> | > Thanks,
> | >
> | > Billo
> | >
> | >
> |
There is a minimum safe pressure. Once that is reached, wear starts
happening fast.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Joseph P wrote:
>
> So, in my 98 TJ, my oil pressure at idle is pretty low compared to
> what it used to be (I think). It seems to be down around 30psi at
> idle, but at speed it is up around 50 or so. Is this the type of
> indicator we are talking about for worn crank bearings, assuming of
> course my pump and pressure sending unit are good. It only has 66k
> miles on it (around there, would have to double check.)
>
> --
> --
> Joe Pribe
> NC
> jpribe 'at' nc.rr.com <you know the drill
> jegp 'at' hotmail.com < at is really @
> ---- I Love My O|||||||O TJ
>
> "CRWLR" <beerman@yahoo.com> wrote in message
> news:104hrntpkjur30b@corp.supernews.com...
> | Think of the sprinklers out in your yard.
> |
> | There is probably about 10 of them connected to a single valve, and
> you have
> | perhaps 6 valves to water the front and rear lawns, and the planter
> boxes.
> | There is something like 60 psi on the system, and if there are too
> many
> | sprinkler heads on a single line, then none of the sprinklers will
> spray
> | very well because the pressure at any one head will drop relative to
> the
> | pressure there would be if there were fewer heads. If one head blows
> off,
> | then the water flow through the remaining heads will drop.
> |
> | Your bearings are kinda similar. There are a number of particular
> sized
> | holes (gallies) that the oil will flow through. If a bearing wears,
> then the
> | oil pressure will drop because the amount of oil that can flow there
> will
> | increase. If the crank and bearings are in good shape, then the oil
> galley
> | is a known size. but, if the bearing or crank journal wears, then
> the galley
> | effectively becomes larger because oil can not fit in the space
> between the
> | crank and the bearing face. When this happens, there is less oil for
> some
> | location further down the line. Basically, the oil pressure is
> dependent
> | upon having specific sizes of oriffices to be pushed through, if one
> or more
> | of those oriffices can accomodate more oil that it is designed to,
> then the
> | remaining oriffices will get less oil because the amount of oil
> available is
> | fixed due to the capacity of the oil pump.
> |
> | If the bearings wore a little bit, then theoritically one could
> install a
> | higher capacity pump to raise the amount of oil available. the
> problem with
> | that theory is that the worn parts will continue to wear, requiring
> | increasingly larger capacity pumps. At some point, the ability of
> the pump
> | to do its job would exceed the ability of the oil passages to carry
> oil, and
> | the pump would cavatate, and you would still have the worn bearings
> that
> | allowed the oil to bypass all of the other places that it ought to
> be going.
> | If you connected a fire hose to your sprinkler system that had lost
> a head,
> | the other heads might get some water, but the one that was broken
> would
> | still be broken and lots of water would be wasted. (there is a
> significant
> | difference in the oil pump and the fire hose, the pump is in a
> closed system
> | so there wouldn't be the waste, but what these have in common is
> that there
> | would be lots of oil in a place that couldn't benefit from it, and
> minimal
> | oil in a place that needs it badly.)
> |
> |
> |
> |
> |
> | "William Oliveri" <wuji@bigvalley.net> wrote in message
> | news:c2am04$1qphp5$1@ID-193866.news.uni-berlin.de...
> | > Mike mentioned this in another post and it's not coming through my
> little
> | > pea brain how that works. How does worn bearings produce low oil
> | pressure?
> | > What's the relation?
> | >
> | >
> | > Thanks,
> | >
> | > Billo
> | >
> | >
> |
#19
Guest
Posts: n/a
Re: How does low oil pressure indicate bad bearings?
Yes, the oil pressure will get slowly lower over time as parts wear.
There is a minimum safe pressure. Once that is reached, wear starts
happening fast.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Joseph P wrote:
>
> So, in my 98 TJ, my oil pressure at idle is pretty low compared to
> what it used to be (I think). It seems to be down around 30psi at
> idle, but at speed it is up around 50 or so. Is this the type of
> indicator we are talking about for worn crank bearings, assuming of
> course my pump and pressure sending unit are good. It only has 66k
> miles on it (around there, would have to double check.)
>
> --
> --
> Joe Pribe
> NC
> jpribe 'at' nc.rr.com <you know the drill
> jegp 'at' hotmail.com < at is really @
> ---- I Love My O|||||||O TJ
>
> "CRWLR" <beerman@yahoo.com> wrote in message
> news:104hrntpkjur30b@corp.supernews.com...
> | Think of the sprinklers out in your yard.
> |
> | There is probably about 10 of them connected to a single valve, and
> you have
> | perhaps 6 valves to water the front and rear lawns, and the planter
> boxes.
> | There is something like 60 psi on the system, and if there are too
> many
> | sprinkler heads on a single line, then none of the sprinklers will
> spray
> | very well because the pressure at any one head will drop relative to
> the
> | pressure there would be if there were fewer heads. If one head blows
> off,
> | then the water flow through the remaining heads will drop.
> |
> | Your bearings are kinda similar. There are a number of particular
> sized
> | holes (gallies) that the oil will flow through. If a bearing wears,
> then the
> | oil pressure will drop because the amount of oil that can flow there
> will
> | increase. If the crank and bearings are in good shape, then the oil
> galley
> | is a known size. but, if the bearing or crank journal wears, then
> the galley
> | effectively becomes larger because oil can not fit in the space
> between the
> | crank and the bearing face. When this happens, there is less oil for
> some
> | location further down the line. Basically, the oil pressure is
> dependent
> | upon having specific sizes of oriffices to be pushed through, if one
> or more
> | of those oriffices can accomodate more oil that it is designed to,
> then the
> | remaining oriffices will get less oil because the amount of oil
> available is
> | fixed due to the capacity of the oil pump.
> |
> | If the bearings wore a little bit, then theoritically one could
> install a
> | higher capacity pump to raise the amount of oil available. the
> problem with
> | that theory is that the worn parts will continue to wear, requiring
> | increasingly larger capacity pumps. At some point, the ability of
> the pump
> | to do its job would exceed the ability of the oil passages to carry
> oil, and
> | the pump would cavatate, and you would still have the worn bearings
> that
> | allowed the oil to bypass all of the other places that it ought to
> be going.
> | If you connected a fire hose to your sprinkler system that had lost
> a head,
> | the other heads might get some water, but the one that was broken
> would
> | still be broken and lots of water would be wasted. (there is a
> significant
> | difference in the oil pump and the fire hose, the pump is in a
> closed system
> | so there wouldn't be the waste, but what these have in common is
> that there
> | would be lots of oil in a place that couldn't benefit from it, and
> minimal
> | oil in a place that needs it badly.)
> |
> |
> |
> |
> |
> | "William Oliveri" <wuji@bigvalley.net> wrote in message
> | news:c2am04$1qphp5$1@ID-193866.news.uni-berlin.de...
> | > Mike mentioned this in another post and it's not coming through my
> little
> | > pea brain how that works. How does worn bearings produce low oil
> | pressure?
> | > What's the relation?
> | >
> | >
> | > Thanks,
> | >
> | > Billo
> | >
> | >
> |
There is a minimum safe pressure. Once that is reached, wear starts
happening fast.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Joseph P wrote:
>
> So, in my 98 TJ, my oil pressure at idle is pretty low compared to
> what it used to be (I think). It seems to be down around 30psi at
> idle, but at speed it is up around 50 or so. Is this the type of
> indicator we are talking about for worn crank bearings, assuming of
> course my pump and pressure sending unit are good. It only has 66k
> miles on it (around there, would have to double check.)
>
> --
> --
> Joe Pribe
> NC
> jpribe 'at' nc.rr.com <you know the drill
> jegp 'at' hotmail.com < at is really @
> ---- I Love My O|||||||O TJ
>
> "CRWLR" <beerman@yahoo.com> wrote in message
> news:104hrntpkjur30b@corp.supernews.com...
> | Think of the sprinklers out in your yard.
> |
> | There is probably about 10 of them connected to a single valve, and
> you have
> | perhaps 6 valves to water the front and rear lawns, and the planter
> boxes.
> | There is something like 60 psi on the system, and if there are too
> many
> | sprinkler heads on a single line, then none of the sprinklers will
> spray
> | very well because the pressure at any one head will drop relative to
> the
> | pressure there would be if there were fewer heads. If one head blows
> off,
> | then the water flow through the remaining heads will drop.
> |
> | Your bearings are kinda similar. There are a number of particular
> sized
> | holes (gallies) that the oil will flow through. If a bearing wears,
> then the
> | oil pressure will drop because the amount of oil that can flow there
> will
> | increase. If the crank and bearings are in good shape, then the oil
> galley
> | is a known size. but, if the bearing or crank journal wears, then
> the galley
> | effectively becomes larger because oil can not fit in the space
> between the
> | crank and the bearing face. When this happens, there is less oil for
> some
> | location further down the line. Basically, the oil pressure is
> dependent
> | upon having specific sizes of oriffices to be pushed through, if one
> or more
> | of those oriffices can accomodate more oil that it is designed to,
> then the
> | remaining oriffices will get less oil because the amount of oil
> available is
> | fixed due to the capacity of the oil pump.
> |
> | If the bearings wore a little bit, then theoritically one could
> install a
> | higher capacity pump to raise the amount of oil available. the
> problem with
> | that theory is that the worn parts will continue to wear, requiring
> | increasingly larger capacity pumps. At some point, the ability of
> the pump
> | to do its job would exceed the ability of the oil passages to carry
> oil, and
> | the pump would cavatate, and you would still have the worn bearings
> that
> | allowed the oil to bypass all of the other places that it ought to
> be going.
> | If you connected a fire hose to your sprinkler system that had lost
> a head,
> | the other heads might get some water, but the one that was broken
> would
> | still be broken and lots of water would be wasted. (there is a
> significant
> | difference in the oil pump and the fire hose, the pump is in a
> closed system
> | so there wouldn't be the waste, but what these have in common is
> that there
> | would be lots of oil in a place that couldn't benefit from it, and
> minimal
> | oil in a place that needs it badly.)
> |
> |
> |
> |
> |
> | "William Oliveri" <wuji@bigvalley.net> wrote in message
> | news:c2am04$1qphp5$1@ID-193866.news.uni-berlin.de...
> | > Mike mentioned this in another post and it's not coming through my
> little
> | > pea brain how that works. How does worn bearings produce low oil
> | pressure?
> | > What's the relation?
> | >
> | >
> | > Thanks,
> | >
> | > Billo
> | >
> | >
> |
#20
Guest
Posts: n/a
Re: How does low oil pressure indicate bad bearings?
But cholesterol, decreasing the size of the vessel, will increase BP (it
will also give a false high reading because it causes the vessel to be
harder to compress - but that's another topic)
--
Carlo F. Serusa, Jr. RPh
carlo.jr at comcast DOTnet
'98 Sahara TJ - '89 YJ - '79 Scout II
O|||||||O
'92 Explorer '65 Mustang
"SB" <chicbears@hotmail.com> wrote in message
news:%Ok2c.163530$Qg7.128071@news04.bloor.is.net.c able.rogers.com...
> But you can't lower your blood pressure by poking a hole in an artery!!
> makes sense to an irishman....but makes a mess too!
>
> sb
>
> "Carlo" <carlo.jr@comcast.net> wrote in message
> news:XL6dnWh8PdHoztTdRVn-ig@comcast.com...
> > hmmmmmmm...........................similar situation with your blood
> > pressure
> >
> > --
> > Carlo F. Serusa, Jr. RPh
> > carlo.jr at comcast DOTnet
> > '98 Sahara TJ - '89 YJ - '79 Scout II
> > O|||||||O
> > '92 Explorer '65 Mustang
> >
> >
> > "Mike Romain" <romainm@sympatico.ca> wrote in message
> > news:4048DD79.829D4BF1@sympatico.ca...
> > > Oil pumps have to have resistance to build up pressure or the oil just
> > > flows free at 0 psi.
> > >
> > > The oil channels lead to the bearings have a 'little' restriction, but
> > > not much. The big restriction is at the bearing faces.
> > >
> > > The biggest bearings are on the crank so when the bearing faces get
> > > worn, the restriction goes away and the oil flows past faster and
under
> > > lower psi.
> > >
> > > This makes for a lower pressure reading on a gauge in the system.
> > >
> > > Mike
> > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > > 88 Cherokee 235 BFG AT's
> > >
> > > William Oliveri wrote:
> > > >
> > > > Mike mentioned this in another post and it's not coming through my
> > little
> > > > pea brain how that works. How does worn bearings produce low oil
> > pressure?
> > > > What's the relation?
> > > >
> > > > Thanks,
> > > >
> > > > Billo
> >
> >
>
>
will also give a false high reading because it causes the vessel to be
harder to compress - but that's another topic)
--
Carlo F. Serusa, Jr. RPh
carlo.jr at comcast DOTnet
'98 Sahara TJ - '89 YJ - '79 Scout II
O|||||||O
'92 Explorer '65 Mustang
"SB" <chicbears@hotmail.com> wrote in message
news:%Ok2c.163530$Qg7.128071@news04.bloor.is.net.c able.rogers.com...
> But you can't lower your blood pressure by poking a hole in an artery!!
> makes sense to an irishman....but makes a mess too!
>
> sb
>
> "Carlo" <carlo.jr@comcast.net> wrote in message
> news:XL6dnWh8PdHoztTdRVn-ig@comcast.com...
> > hmmmmmmm...........................similar situation with your blood
> > pressure
> >
> > --
> > Carlo F. Serusa, Jr. RPh
> > carlo.jr at comcast DOTnet
> > '98 Sahara TJ - '89 YJ - '79 Scout II
> > O|||||||O
> > '92 Explorer '65 Mustang
> >
> >
> > "Mike Romain" <romainm@sympatico.ca> wrote in message
> > news:4048DD79.829D4BF1@sympatico.ca...
> > > Oil pumps have to have resistance to build up pressure or the oil just
> > > flows free at 0 psi.
> > >
> > > The oil channels lead to the bearings have a 'little' restriction, but
> > > not much. The big restriction is at the bearing faces.
> > >
> > > The biggest bearings are on the crank so when the bearing faces get
> > > worn, the restriction goes away and the oil flows past faster and
under
> > > lower psi.
> > >
> > > This makes for a lower pressure reading on a gauge in the system.
> > >
> > > Mike
> > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > > 88 Cherokee 235 BFG AT's
> > >
> > > William Oliveri wrote:
> > > >
> > > > Mike mentioned this in another post and it's not coming through my
> > little
> > > > pea brain how that works. How does worn bearings produce low oil
> > pressure?
> > > > What's the relation?
> > > >
> > > > Thanks,
> > > >
> > > > Billo
> >
> >
>
>