Old car has a low oil level sensor, which has never really worked
properly. And spares for it NLA.

It has a probe in the sump about 2" long, which merely screws in. Doesn't
tell you the oil level as such - just warns if it gets too low.

I've looked for a modern aftermarket set (probe plus electronics) but
can't find anything.

I've also no idea on the principle of how it works.

Anyone know of anything that could be adapted? Electronics obviously need
to be able to work from a car supply.

--
*Always drink upstream from the herd *

Dave Plowman London SW
To e-mail, change noise into sound.

If it never worked maybe it's not surprising spares aren't available. Apart from screwing in are there any other connections to it and what diameter might it be?
There used to be a trade magazine called what's new in process control. If it's still on the go the adverts in there might be worth digging through?

On 21/05/2019 10:48, Dave Plowman (News) wrote:
Old car has a low oil level sensor, which has never really worked
properly. And spares for it NLA.

It has a probe in the sump about 2" long, which merely screws in. Doesn't
tell you the oil level as such - just warns if it gets too low.

I've looked for a modern aftermarket set (probe plus electronics) but
can't find anything.

I've also no idea on the principle of how it works.

Is the sensor a cylinder the oil can enter? If so I'd suspect it
measures the changes in capacitance between the case and a central
electrode as the level of oil changes.

Don't ask me about the electronics to convert that to a measurable
signal: I opted out of electronics in favour of what seemed more useful
at the time (eg nuclear).

Anyone know of anything that could be adapted? Electronics obviously need
to be able to work from a car supply.


Similar sensors from other cars of the period - eg Buicks?

--
Robin
reply-to address is (intended to be) valid

Dave Plowman (News) wrote:
Old car has a low oil level sensor, which has never really worked
properly. And spares for it NLA.

It has a probe in the sump about 2" long, which merely screws in. Doesn't
tell you the oil level as such - just warns if it gets too low.

I've looked for a modern aftermarket set (probe plus electronics) but
can't find anything.

I've also no idea on the principle of how it works.

Anyone know of anything that could be adapted? Electronics obviously need
to be able to work from a car supply.


If it's an old car, I'd guess it was something mechanical, like a switch
with a diaphragm, or a float, or something. I'm surprised you didn't
ask in uk.rec.cars.maintenance - I'm sure I've seen you in there before,
and it's not completely dead.

In article ,
Dan S. MacAbre wrote:
If it's an old car, I'd guess it was something mechanical, like a switch
with a diaphragm, or a float, or something. I'm surprised you didn't
ask in uk.rec.cars.maintenance - I'm sure I've seen you in there before,
and it's not completely dead.

Sadly not something as simple as a float. As I said, I dunno just how it
works.

Reason I'm asking here is perhaps a fluid sensor from something like an
oil tank for central heating? Or whatever?

--
*Income tax service - We‘ve got what it takes to take what you've got.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Robin wrote:
On 21/05/2019 10:48, Dave Plowman (News) wrote:
Old car has a low oil level sensor, which has never really worked
properly. And spares for it NLA.

It has a probe in the sump about 2" long, which merely screws in. Doesn't
tell you the oil level as such - just warns if it gets too low.

I've looked for a modern aftermarket set (probe plus electronics) but
can't find anything.

I've also no idea on the principle of how it works.

Is the sensor a cylinder the oil can enter? If so I'd suspect it
measures the changes in capacitance between the case and a central
electrode as the level of oil changes.

No - it is a sealed unit. Hence not being able to guess just how it works.
Or not.

Don't ask me about the electronics to convert that to a measurable
signal: I opted out of electronics in favour of what seemed more useful
at the time (eg nuclear).

Anyone know of anything that could be adapted? Electronics obviously
need to be able to work from a car supply.


Similar sensors from other cars of the period - eg Buicks?

As I said anything suitable has been NLA for some time. When I bought the
car at about 3 years old, BL couldn't supply a spare sensor.

--
*Always borrow money from pessimists - they don't expect it back *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) brought next idea :
Sadly not something as simple as a float. As I said, I dunno just how it
works.

Reason I'm asking here is perhaps a fluid sensor from something like an
oil tank for central heating? Or whatever?

The only one I have ever come across, used a pipe dipping down to the
oil level. At the dash, you tugged on a button which had a concentric
red/green indicator. The outer section stayed in as you pulled, showing
green if the oil level was OK and the end of the tube below the oil
level. If above the outer section would pull out showing red. You had
to use it while the engine was off. It worked on the principle of the
oil being harder to suck up the pipe, than air would be if the pipe
ended in air.

Dave Plowman (News) wrote:
In article ,
Dan S. MacAbre wrote:
If it's an old car, I'd guess it was something mechanical, like a switch
with a diaphragm, or a float, or something. I'm surprised you didn't
ask in uk.rec.cars.maintenance - I'm sure I've seen you in there before,
and it's not completely dead.

Sadly not something as simple as a float. As I said, I dunno just how it
works.

Reason I'm asking here is perhaps a fluid sensor from something like an
oil tank for central heating? Or whatever?


Well, I didn't really think a float would do the job in those conditions
(having had them puncture themselves in old carbs), but it was just an
example of something mechanical that some optimist designer might have
dreamed up in the past. I'd guess something that relied on negative
pressure produced by suction to keep the contacts in a certain position.
The missus once had a Capri, and I'm sure it had such a thing.

Dave Plowman (News) wrote:

Old car has a low oil level sensor, which has never really worked
properly.
Anyone know of anything that could be adapted?

The phrase "electronic dipstick" turns up a few possible interesting
devices, e.g.

http://www.raventechcorp.com/Products.html

In article ,
Andy Burns wrote:
Dave Plowman (News) wrote:

Old car has a low oil level sensor, which has never really worked
properly.
Anyone know of anything that could be adapted?

The phrase "electronic dipstick" turns up a few possible interesting
devices, e.g.

http://www.raventechcorp.com/Products.html

Interesting, but rather too sophisticated for my use. ;-)

--
*A dog's not just for Christmas, it's alright on a Friday night too*

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Dan S. MacAbre wrote:
Dave Plowman (News) wrote:
In article ,
Dan S. MacAbre wrote:
If it's an old car, I'd guess it was something mechanical, like a switch
with a diaphragm, or a float, or something. I'm surprised you didn't
ask in uk.rec.cars.maintenance - I'm sure I've seen you in there before,
and it's not completely dead.

Sadly not something as simple as a float. As I said, I dunno just how it
works.

Reason I'm asking here is perhaps a fluid sensor from something like an
oil tank for central heating? Or whatever?


Well, I didn't really think a float would do the job in those conditions
(having had them puncture themselves in old carbs), but it was just an
example of something mechanical that some optimist designer might have
dreamed up in the past. I'd guess something that relied on negative
pressure produced by suction to keep the contacts in a certain position.
The missus once had a Capri, and I'm sure it had such a thing.

I did have an old Bentley with a float inside the sump. Just like in the
fuel tank. Press a button next to the fuel gauge and it read oil level.
Worked pretty well too.

My everyday car has an oil level system too - and no dipstick. But again,
more than I need for the old car. Just want the original idea of a low
level warning. Not just for me, but to do an article for the club mag. If
I can find a reasonably easy to fit substitute.

The sensor on the outside is simply a sealed brass tube which fits
horizontally in the sump via a threaded boss - I assume at the minimum
oil level. With two wires going into it. BL manual no help as to how it
actually works. The electronics (located behind the instruments) is badged
Plektron.

--
*A bicycle can't stand alone because it's two tyred.*

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article ,
Dan S. MacAbre wrote:
Dave Plowman (News) wrote:
In article ,
Dan S. MacAbre wrote:
If it's an old car, I'd guess it was something mechanical, like a switch
with a diaphragm, or a float, or something. I'm surprised you didn't
ask in uk.rec.cars.maintenance - I'm sure I've seen you in there before,
and it's not completely dead.

Sadly not something as simple as a float. As I said, I dunno just how it
works.

Reason I'm asking here is perhaps a fluid sensor from something like an
oil tank for central heating? Or whatever?


Well, I didn't really think a float would do the job in those conditions
(having had them puncture themselves in old carbs), but it was just an
example of something mechanical that some optimist designer might have
dreamed up in the past. I'd guess something that relied on negative
pressure produced by suction to keep the contacts in a certain position.
The missus once had a Capri, and I'm sure it had such a thing.

I did have an old Bentley with a float inside the sump. Just like in the
fuel tank. Press a button next to the fuel gauge and it read oil level.
Worked pretty well too.

My everyday car has an oil level system too - and no dipstick. But again,
more than I need for the old car. Just want the original idea of a low
level warning. Not just for me, but to do an article for the club mag. If
I can find a reasonably easy to fit substitute.

The sensor on the outside is simply a sealed brass tube which fits
horizontally in the sump via a threaded boss - I assume at the minimum
oil level. With two wires going into it. BL manual no help as to how it
actually works. The electronics (located behind the instruments) is badged
Plektron.


Our first car (an ancient Avenger) didn't have a working fuel gauge -
you had to shove a pipe into the filler and see by the wetness where the
petrol had come up to. When I finally got round to fixing it, it
transpired that whoever had put the seats in had crushed the wire
between the seat frame and the floor. It was so obvious, we wondered if
they'd done it just for the hell of it.

Dave Plowman wrote:

My everyday car has an oil level system too - and no dipstick

Same with my present and previous cars, I gather the dipstick tube is
now relegated to a handy way of sucking the old oil out at service time,
even the oil filter is positioned at the top of the engine to avoid any
pesky bending down to reach it.

I can remotely monitor various readings from the car on my phone, it
seemed like the oil was drained within a minute of them starting to
service it ...

On Tuesday, 21 May 2019 10:48:29 UTC+1, Dave Plowman (News) wrote:
Old car has a low oil level sensor, which has never really worked
properly. And spares for it NLA.

It has a probe in the sump about 2" long, which merely screws in. Doesn't
tell you the oil level as such - just warns if it gets too low.

I've looked for a modern aftermarket set (probe plus electronics) but
can't find anything.

I've also no idea on the principle of how it works.

It is connected to the inlet manifold with apipe
When the hole is immersed in oil, a vacuum is created.
When it it exposed, there is normal air pressure.

So all there is, is a switch measuring the vacuum or lack thereof.

On Tue, 21 May 2019 18:22:08 +0100, "Dave Plowman (News)"
wrote:


The sensor on the outside is simply a sealed brass tube which fits
horizontally in the sump via a threaded boss - I assume at the minimum
oil level. With two wires going into it. BL manual no help as to how it
actually works. The electronics (located behind the instruments) is badged
Plektron.

Sure it's not Pektron?

They did a ****load of electronics / relays etc for serveral UK car
manufacturers I'm aware of their products on the Lotus Elise / Elan / Esprit and
the K series engined MG/Rover)

Still around in Derby

https://www.pektron.com/

--

On Tue, 21 May 2019 10:48:22 +0100, Dave Plowman (News) wrote:

I've also no idea on the principle of how it works.

Another curious problem. What have we got?

A 2" sealed probe.
Material?
Is the probe electrically connected to the mounting boss?

Screws horizontally into the sump.
Above/below/at the minimum level?

2 wires.
Is one connected to the probe body and/or mounting boss?
Are the wires open/short circuit or have some resistance?
Does the state change/alter between plenty of oil and not
enough
oil?

Digging about for the "low oil" cut offs for small engines, as I
thought my diesel genset had one and that was just a bare probe so
might lead some where. I found that they are mostly float switches or
pressure operated but there is also an "electro-vibration"
type:

http://outdoorpowerinfo.com/repairs/...l_shutdown.asp
http://outdoorpowerinfo.com/repairs/...oil_shutdown.a
sp

Peizo element mounted in tube, with oil around less vibration, no oil
more vibration, control box to generate appropiate signal. As it's
piezo element one assumes if you took the probe out connected it to a
'scope and gently tapped or vibrated the probe you'd see something on
the 'scope.

--
Cheers
Dave.

In article l.net,
Dave Liquorice wrote:
On Tue, 21 May 2019 10:48:22 +0100, Dave Plowman (News) wrote:

I've also no idea on the principle of how it works.

Another curious problem. What have we got?

A 2" sealed probe.
Material?

Brass tube. If you want, a bit like a large CTS.

Is the probe electrically connected to the mounting boss?

It is screwed into the sump, so will have at least some degree of
connection to that.

Screws horizontally into the sump.
Above/below/at the minimum level?

Impossible to tell. A guess would be at about the minimum level, by
looking at the position on the sump.

2 wires.
Is one connected to the probe body and/or mounting boss?
Are the wires open/short circuit or have some resistance?
Does the state change/alter between plenty of oil and not
enough
oil?

There are two wires from it.

Never had a working one to do any tests on. Been NLA for ages, and used
ones expensive.

Digging about for the "low oil" cut offs for small engines, as I
thought my diesel genset had one and that was just a bare probe so
might lead some where. I found that they are mostly float switches or
pressure operated but there is also an "electro-vibration"
type:

http://outdoorpowerinfo.com/repairs/...l_shutdown.asp
http://outdoorpowerinfo.com/repairs/...oil_shutdown.a
sp

Peizo element mounted in tube, with oil around less vibration, no oil
more vibration, control box to generate appropiate signal. As it's
piezo element one assumes if you took the probe out connected it to a
'scope and gently tapped or vibrated the probe you'd see something on
the 'scope.

--
*See no evil, Hear no evil, Date no evil.

Dave Plowman London SW
To e-mail, change noise into sound.

On 21/05/2019 13:44, Dave Plowman (News) wrote:
In article ,
Robin wrote:
On 21/05/2019 10:48, Dave Plowman (News) wrote:
Old car has a low oil level sensor, which has never really worked
properly. And spares for it NLA.

It has a probe in the sump about 2" long, which merely screws in. Doesn't
tell you the oil level as such - just warns if it gets too low.

I've looked for a modern aftermarket set (probe plus electronics) but
can't find anything.

I've also no idea on the principle of how it works.

Is the sensor a cylinder the oil can enter? If so I'd suspect it
measures the changes in capacitance between the case and a central
electrode as the level of oil changes.

No - it is a sealed unit. Hence not being able to guess just how it works.
Or not.

Could still be a capacitive sensor but with the sump as the other
"plate". Is one of the sensor's wires short-circuit to the sump?

Don't ask me about the electronics to convert that to a measurable
signal: I opted out of electronics in favour of what seemed more useful
at the time (eg nuclear).

Anyone know of anything that could be adapted? Electronics obviously
need to be able to work from a car supply.


Similar sensors from other cars of the period - eg Buicks?

As I said anything suitable has been NLA for some time. When I bought the
car at about 3 years old, BL couldn't supply a spare sensor.


I did say "from /other/ cars of the period" - which was in response to
your "anything that could be /adapted/" [emphases added].

--
Robin
reply-to address is (intended to be) valid

In article ,
Jethro_uk wrote:
On Wed, 22 May 2019 11:03:17 +0100, Dave Plowman (News) wrote:

There are two wires from it.

Sounds exactly like the arrangement I described upthread. A current is
pushed down the wires to the heating element and as long as the circuit
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In article ,
Robin wrote:
Similar sensors from other cars of the period - eg Buicks?

As I said anything suitable has been NLA for some time. When I bought
the car at about 3 years old, BL couldn't supply a spare sensor.


I did say "from /other/ cars of the period" - which was in response to
your "anything that could be /adapted/" [emphases added].

I'd guess electronics etc have improved in 40 years or so and was hoping
for something more modern - and reliable.

--
*Why 'that tie suits you' but 'those shoes suit you'?*

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
The Other Mike wrote:
On Tue, 21 May 2019 18:22:08 +0100, "Dave Plowman (News)"
wrote:


The sensor on the outside is simply a sealed brass tube which fits
horizontally in the sump via a threaded boss - I assume at the minimum
oil level. With two wires going into it. BL manual no help as to how it
actually works. The electronics (located behind the instruments) is
badged Plektron.

Sure it's not Pektron?

Yup - sorry for the brain fart.

They did a ****load of electronics / relays etc for serveral UK car
manufacturers I'm aware of their products on the Lotus Elise / Elan /
Esprit and the K series engined MG/Rover)

Still around in Derby

https://www.pektron.com/

Ah. I'd never heard of them before.

--
*Out of my mind. Back in five minutes.

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman wrote:

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You wot?

In article ,
Andy Burns wrote:
Dave Plowman wrote:

Q
##
# ##Q
####S#A
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##########
##:##S#A
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You wot?

No idea at all. Blame it on BT. I do.

This is the post from my log:-

In article ,
Jethro_uk wrote:
On Wed, 22 May 2019 11:03:17 +0100, Dave Plowman (News) wrote:

There are two wires from it.

Sounds exactly like the arrangement I described upthread. A current is
pushed down the wires to the heating element and as long as the circuit
stays closed you have oil.

Could well be. On a working one, the warning light flashes for a few
seconds before giving a reading. Could be while it heats up.

--
*Snowmen fall from Heaven unassembled*

Dave Plowman London SW
To e-mail, change noise into sound.

--
*Santa Claus has the right idea. Visit people only once a year.

Dave Plowman London SW
To e-mail, change noise into sound.