"Sharon Cooke" <scooke (AT) cox (DOT) net> wrote


Ford hasn't used anything but the single position indicator type gauge
for at least a decade (except on HD trucks). And it is not just Ford,
GM has also gone to this type of gauge, as has Nissan. Unless you are
going to spend the money to calibrate the sender and gauge system and
educate the users, having a "real" gauge that moves around is a waste.
The last variable gauge I had in a Chrysler was totally worthless. It
moved around all over the place, but the readings were only loosely
related to the actual engine oil pressure. It worried me greatly. I
finally installed an actual direct reading pressure gauge to verify
there was no actual problem.

Ed

"Ashton Crusher" <demi (AT) moore (DOT) net> wrote


Ford never recommended 10W30 for a 1999 4.6L engine. The oil
originally recommended in 1999 was 5W30 (Ford Spec
WSS-M2C153-G). A later TSB recommended the use of 5W20 oil in 1999
4.6L engines. I've never understood why anyone uses 10W30 instead of
5W30. At operating temperature there is virtually no difference in
viscosity. When cold, both oils are more viscous than either oil is
when it is warm, but the 5W30 is slightly less viscous and therefore a
better choice for a cold engine. I've never seen any claims that 5W30
is significantly more likely to break down than 10W30 (unlike 10W40
which was alleged to suffer from significant break down problems - at
least when originally introduced). The only reason I can see for using
10W30 over 5W30 is cost ($0.10 to $0.20 a quart).

In the US the commonly available 5w20 Ford Oil is a Synthetic Blend
(SAE 5W-20 Premium Synthetic Blend Motor Oil - Red Bottle). In Canada
the commonly available Ford 5W20 oil is a straight non-synthetic oil
(SAE 5W-30 Super Premium Motor Oil - black bottle). I am not sure why
there is a difference (suppliers perhaps). However, even the
non-synthetic blend version is supposedly a very good oil.

Ed

C. E. White wrote:
There are people that believe knowing the engine’s oil pressure is vey
important, and will go to some lengths to get it. See:
http://neptune.spacebears.com/cars/s.../oilgauge.html
and:
http://www.miata.net/garage/opg.html


All of my vehicles have functional oil pressure gauges AND the idiot lights.
It really makes me nervous to drive a vehicle any distance at highway
speed that doesn’t have an actual oil pressure gauge. Oil pressure in an
engine can decline over time due to bearing wear, oil pump, clogged sump
screen, filter, etc., and if the idiot light comes on at 70 mph, it’s
usually time for a new engine.

"Sharon Cooke" <scooke (AT) cox (DOT) net> wrote


All that is fine for you, since you have may know the correct oil
pressure and might actually take action if it is not correct. For the
typical driver what does he learn from a full function oil pressure
gauge? How many people know what the minimum acceptable idle pressure
is. How about the acceptable 2000 rpm pressure is? Ford specifies that
the oil pressure for a 4.6L V-8 should be 40 to 60 psi at 2000 rpm
with the oil hot (and I am assuming the use of 5W20 oil). Is there any
reason to think 40 psi is better than 60 psi? Ford's assumption is
that if you have enough oil pressure at idle to close the switch for
the indicator, that the oil pump is working and the filter is not
plugged. If the pump is working and oil is flowing at idle, what could
be wrong that would affect lubrication at higher rpms? Worn pump? If
the pump is worn so badly that it can't make decent pressure at 2000
rpm, it probably can't make 7 psi at idle - and the light should come
on. Worn bearings? If the bearing are worn so badly that the pump
can't produce enough oil to keep up the pressure at 2000 rpm, then the
engine is already toast.

It is important that your oil pump supplies enough volume of oil to
the places where it is needed. Pressure is almost irrelevant as long
as you maintain an adequate flow. You are using the oil pressure
reading as a indicator that this is happening, but it is only a
secondary indicator. You can have high oil pressure and still not
provide proper lubrication. And you can have low pressure while
providing adequate lubrication. People get into the "more is better"
mode, but in the case of oil pressure this is not always true.

Consumer grade electrical oil pressure gauges are notoriously
inaccurate - particularly over a long period of time. They may well
have better than 5% accuracy when new, but over a period of time they
drift significantly. Mechanical gauges are better at remaining
accurate over time, but then you have the danger of a failed oil line.
It is no fun having hot oil dribble onto your feet.

"Real" variable reading oil pressure gauges might be useful to a small
number of individuals who understand the readings, who actually pay
attention to the readings, and who might actually take some action
based on the readings, BUT for the vast majority of car owners, the
go/no go type of gauge is the proper choice. To me the go/no go type
of gauge is better than the "low oil pressure" light alone, since it
is a positive indicator that you have the minimum oil pressure.

Ed

C. E. White wrote:
as an analog gauge? Probably LESS useful than the idiot light, except as
a feel good kind of thing, since it won’t even call attention to itself
as well as an idiot light if something goes wrong, and is also useless
for indicating a pressure drop trend.
As far as knowing oil pressure ranges on a real gauge (electric is just
as "real" as a mechanical one) for a particular vehicle go, I do know,
since I have the factory service manuals for all my vehicles. The
electric gauges DO read a hair low compared to my Snap-On test
mechanical gauge, but so what? I’d rather have them read a little too
low than a little too high. I also check the electric gauges(s) readings
with the mechanical test gauge every time I change the oil and filter at
10K miles; Mobil One 5W30 on all.

Sharon Cooke wrote:

Your missing his point. You are among the 2% of people that actually look at, know
how to interpret, and will respond to, a real oil pressure gauge. Most drivers haven't
a clue. How many times have you heard inquiries that started with "My xxxxx light has
been coming on for about a month..." For the majority, the go/no-go gauge or light is
actually better than a gauge. A light will at least get their attention.

"Sharon Cooke" <scooke (AT) cox (DOT) net> wrote


A go/no go gauge is exactly what it is. It is a positive indicator. If
you only have the light, you only have a negative indicator. The light
might not be on because the oil pressure is good, but it might also
might not be on because the light circuit is bad. With the go/no go
type gauge you have a positive indication that you have sufficient
pressure. If the gauge doesn't come up to pressure it might be because
you have no pressure, or it might be because the gauge circuit is bad,
but either way you know something is wrong.

As for indicating trends - you seem to be very attentive and
understand the reasons for oil pressure fluctuations. What percentage
of car owners do you think that applies to?

Well you sound like a really attentive vehicle owner. Now for the big
question - has all this attention to changing oil pressure made any
significant difference? Have you saved an engine because you saw the
oil pressure slowly decreasing over time? For me, I've never had an
oil related failure of any kind. My oldest "vehicle" is a 1981 Ford
7710 Tractor. It just turned over 6000 hours (rated speed for the hour
meter is 1900 rpm). It only has an oil pressure warning light. I've
never really worried that it doesn't have a gauge. One of my newer
tractors has a oil pressure gauge, but it isn't calibrated. It is
backed up by both a light and a warning horn (plus a failure will
display STOP on the main dash display). The gauge is just a bar graph
thing that has no values. It is totally worthless, but it does change
over time. On a hot day when you work the tractor hard, it reads lower
than on a cool day when you are putting around. Over the years, it has
trended lower. But so what? What should I do as a result of the
entirely predictable changes? Nothing is what I've done. The gauge has
been no more useful than just the warning light on the other tractor.

Ed

C. E. White wrote:

Oil pressure trending lower over many years usually just means normal
main bearing and crank wear, but dropping in days or even hours could be
a blown head gasket or failing oil pump. In one of those situations, by
the time the idiot light comes on or the fake gauge SUDDENLY drops to
zero, it's time for a new engine.

The same three vehicles I've had for many years:
1990 Lincoln Mark VII - 158.9K miles
1994 Lincoln Mark VIII - 109.8K miles
1990 Toyota Truck - 237.8K miles
A combined total of over 1/2 million miles with 10K oil changes and ZERO
internal engine problems on any of the vehicles.

I did have the idiot light on the Mark VIII turn on once at 70 mph, but
the OP gauge was showing a steady 60 psi, so I just kept going. When I
got the car up on ramps at home, I found it was the factory oil pressure
snap switch that had failed; without the real OP gauge, I would have
been really inconvenienced out there on I-35 at 2 AM, so I’ll just keep
running with OP gauges in all my vehicles.

I also have voltmeter gauges on all my vehicles, since I don’t trust the
other idiot light for the charging system either.

On Apr 26, 11:20 am, Sharon Cooke <sco... (AT) cox (DOT) net> wrote:

And how often does this happen? I've had a couple of head gaskets fail
in my life, and both times the first symptom was overheating. I
suppose you can get a massive oil leak, but a massive coolant leak
seems more likely. And even when oil pumps were driven off the
distributor gear, gradual failures were uncommon. With todays crank
driven pumps, it is much more likely that an oil pump failure will be
sudden and in that case the light is as good as a gauge.

I haven't had any sort of significant engine failure in over 20 years.
The last time I had one was a 1978 Fiesta with a 140,000 miles. I
managed to burn a piston (clogged EGR, and drving flat out for 35
miles). I have a 35 year old Dodge dump truck with an unknow number of
miles (well over 100,000). The only thing that has failed in the oil
system is the crappy electric oil pressure gauge.

For you it seems like a reasonable thing. You understand what gauge
movements mean and you pay attention to the gauges. I am suggesting
that you are the exception. Most vehicle owners don't pay attention to
the gauges, and when they do, they often misinterpert them. It must
really upset you that car makers are now installing computer
controlled temperature gauges. The gauges appear to move like old
style gauges, but actually the needle position is determined by the
PCM and not the water temperature. Both my current Nissan and Fords
have this sort of gauge. They are not completely go/no go gauges, more
a sort of incremental gauge with the position dictated by the PCM.

I am surprised you don't have an old style ammeter. Voltage meters are
OK, but to be truly useful they need to be calibrated. The OEM ones
just have a few poorly located markings and by the time you figure the
voltage is too low, it can be too late. Even with the poor quality OEM
gauges, if you pay careful attention to the position of the needle you
can determine that it is lower than normal, but again this is only
useful for people who pay attention and understand what voltage gauge
movements imply.

Most OEM gaguges are just for looks. They aren't particularly well
calibrated and in many cases aren't direct reading gauges. It used to
be that the Germans actually included calibrated gauges, but it has
been a couple of decades since I owned a German car. I have no idea
what the Germans are doing these days. In recent years I have owned
Japanese and Domestic cars that use non-calibrated, poorly marked
gauges that are no better than go/no go indicators.

Ed

On Wed, 25 Apr 2007 08:27:00 -0400, "C. E. White"
<cewhite3 (AT) removemindspring (DOT) com> wrote:

The 10W40 today is excellent if you don't try to run it too long. 3500
mile changes are no problem. 7000 mile intervals you are begging for
trouble (but then, I'd not go 7000 on 5W30 either - same viscosity
spread, means same amount of VI improvers, and the same propensity to
"shear".

--
Posted via a free Usenet account from http://www.teranews.com