Should oil in pressure line for gauge go all the way to the gauge?

Hooking up an oil pressure gauge, should the oil go all the way to the
gauge or should there be an air buffer?

Thanks

muzician21 > wrote in news:73fba85d-edcd-4d8e-9305-
:

> Hooking up an oil pressure gauge,


Huh. Useless and dicey aftermarket gauge.


> should the oil go all the way to the
> gauge or should there be an air buffer?
>



ALL the way! /Any/ air is unacceptable.


--
Tegger

"muzician21" > wrote in message
...
> Hooking up an oil pressure gauge, should the oil go all the way to the
> gauge or should there be an air buffer?
>
> Thanks

It shouldn't matter.If there is air in the line, it will be compressed so
that the "air" pressure is the same as the oil pressure.

I don't really like gauges that require running oil lines to the
dash -especially the sort sold in most mass market auto parts stores. I
prefer good quality electical gauges.

Ed

7MGE inline 6 in a Toyota Cressida, the oil pressure light has been
coming on when hot and at low idle, about 30 - 40k out from a rebuild.
Oil sender was replaced new when the engine was built.

Gauge from Advance which I realize you're going to turn up your nose
at is showing really low - like about 5 psi at about 600 - 700 rpm.
Jumps up well over 30 psi at highway speed.

I've always heard 10psi per 1000 rpm as a ROT, seem to be getting
enough pressure at speed but seems low at idle. Am probably going to
change the pump out and see if that cures it. Got a Clevite pump,
anyone have any feelings about them one way or the other?

Thanks

"muzician21" > wrote in message
...
> Hooking up an oil pressure gauge, should the oil go all the way to the
> gauge or should there be an air buffer?
>
> Thanks

Are you hooking up the gauge temporarily to check oil pressure or are you
trying for a permanent installation in the dashboard?

In either case, the oil needs to go all the way to the gauge unless you are
using an electrical sender type gauge.

The downside to using a direct read gauge is that there are additional
potential sources of oil leaks, and leaking hot oil in the instrument panel
can cause burns and make a huge mess.
--

Ray O
(correct punctuation to reply)

"muzician21" > wrote in message
...
> 7MGE inline 6 in a Toyota Cressida, the oil pressure light has been
> coming on when hot and at low idle, about 30 - 40k out from a rebuild.
> Oil sender was replaced new when the engine was built.
>
> Gauge from Advance which I realize you're going to turn up your nose
> at is showing really low - like about 5 psi at about 600 - 700 rpm.
> Jumps up well over 30 psi at highway speed.
>
> I've always heard 10psi per 1000 rpm as a ROT, seem to be getting
> enough pressure at speed but seems low at idle. Am probably going to
> change the pump out and see if that cures it. Got a Clevite pump,
> anyone have any feelings about them one way or the other?
>
> Thanks

The factory repair manual has specs for clearances between the crescent,
impeller, and pump body. Check the clearances before you swap the pump.
Besides a bad pump, excessive bearing clearances can cause low oil pressure.
--

Ray O
(correct punctuation to reply)

Ray O wrote:
> "muzician21" > wrote in message
> ...
>> Hooking up an oil pressure gauge, should the oil go all the way to the
>> gauge or should there be an air buffer?
>>
>> Thanks
>
> Are you hooking up the gauge temporarily to check oil pressure or are you
> trying for a permanent installation in the dashboard?
>
> In either case, the oil needs to go all the way to the gauge unless you are
> using an electrical sender type gauge.
>
> The downside to using a direct read gauge is that there are additional
> potential sources of oil leaks, and leaking hot oil in the instrument panel
> can cause burns and make a huge mess.

Why would having the oil go all the way up to the gauge be a big deal?
Would there always be oil in the line?

"dr_jeff" > wrote in message
> Why would having the oil go all the way up to the gauge be a big deal?
> Would there always be oil in the line?

It wouldnt normally make much difference. If the line, partially filled
with air,
experienced heating or cooling, I guess the expansion or contraction of the
air could be more of a factor than it would be with a tube filled with oil
alone.

"hls" > wrote in
:

>
> "dr_jeff" > wrote in message
>> Why would having the oil go all the way up to the gauge be a big
>> deal? Would there always be oil in the line?
>
> It wouldnt normally make much difference. If the line, partially
> filled with air,
> experienced heating or cooling, I guess the expansion or contraction
> of the air could be more of a factor than it would be with a tube
> filled with oil alone.
>


Air is compressible. Oil is not. Air in the line will result in a falsely
low gauge reading. At least that's what happened to me many years ago when
I added such a device to my car.

--
Tegger

Tegger wrote:
>
> "hls" > wrote in
> :
>
> >
> > "dr_jeff" > wrote in message
> >> Why would having the oil go all the way up to the gauge be a big
> >> deal? Would there always be oil in the line?
> >
> > It wouldnt normally make much difference. If the line, partially
> > filled with air,
> > experienced heating or cooling, I guess the expansion or contraction
> > of the air could be more of a factor than it would be with a tube
> > filled with oil alone.
> >
>
> Air is compressible. Oil is not. Air in the line will result in a falsely
> low gauge reading. At least that's what happened to me many years ago when
> I added such a device to my car.

How did you make the leap from air is compressible to it will result in
a falsely low gauge reading? You say that as if everyone is supposed to
automagically see the connection.

-jim