Oil Pressure Gauge and Engine death

Steve wrote:
> Chas Hurst wrote:
>
>>
>> I would rather have a reliable oil level display.
>
>
> Every car on the road has one. Its called a "dipstick." Ironically,
> people who don't use that indicator are often called the same thing... ;-)
>
>
> > Low oil pressure is a
>
>> symptom, not a cause, of engine problems.
>
>
> Not always. Low oil pressure may be a symptom of worn bearings. Its also
> an indicator of an oil filter that has collapsed internally, and should
> be replaced. Failure to do so can CAUSE engine damage that could have
> been prevented by reacting to low oil pressure and replacing the $3.00
> filter instead of a $2500 engine. Its an indiator of a blocked or broken
> oil pickup screen that will starve the engine for oil and destroy it,
> but which is very cheap to fix before any damage is done. Its an
> indicator that the dummies at Jiffy Gloop put 5w20 oil in an engine that
> needs 10w30. And on and on and on.
>
>
> A low oil pressure warning is FAR more important than a low oil level
> warning when the engine is operating. For one thing, you can have a
> crankcase full of oil, but the engine will still starve for oil and
> seize if the oil pump isn't pressurizing the oil system, if the filter
> is clogged, if the pickup screen is blocked (eg due to a dented oil
> pan), etc. etc. etc. Conversely, and engine will survive being 3 quarts
> low on oil for a time without any damage whatsoever, provided that
> there's still enough oil to submerge the pickup so that it doesn't draw
> in air (which, by the way, will be indicated by the oil pressure gauge).
>
> You need an oil LEVEL indication when doing routine checks (weekly is a
> good idea). You need an oil PRESSURE indication any time the engine is
> running. Big difference.
>
>
>
>


My oil levels were almost always appropriate. Even when the engine was
shot and the pressure was fluctuating low, the oil quantity was still
appropriate.

--
Thank you,


CL Gilbert
"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16

news wrote:
> CL (dnoyeB) Gilbert wrote:
>
>> Trying to get some lessons learned from my first car 'death.'
>>
>> To make it short, the oil gauge started behaving curiously to me
>> probably last year this time. But since the oil light didnt come on,
>> and the pressure seemed high enough, nothing seemed wrong. This
>> turned out to be bad because the odd pressure behavior was probably a
>> sign of some engine parts that have to do with oil pressure going bad.
>>
>> So the engine is shot. Loud rapping and knocking etc. And now I can
>> see the oil pressure gauge is doing an extreme version of what it was
>> doing last year. needing higher RPM to sustain higher pressure. I
>> couldn't have recognized it without ever seeing it before.
>>
>> The question is, my new car has only the idiot light. Which of course
>> never lit on my blazer since the oil was actually always there. If my
>> engine parts start to wear out and pressure drops, how will I know it?
>> Or am I out of luck without a gauge. I know the light will light when
>> the pressure is low, but that didnt help the blazer because it was
>> more 'odd' pressure behavior than low pressure.
>>
>> Would a good mechanic see the signs early enough?
>>
>> advice?
>>
>
> fwiw, what kind of oil pressure did you have?
>
> the rule of thumb I've heard is 10psi per 1000rpm.
>
> That said, when in doubt, check the manual - I've owned cars that
> specify everything from 20psi to 60psi as "normal" and rpm ranging from
> 2000-4000 for that number.
>
> (Mini rant -> gauges without numbers are just dumb.)
>
> Too high is no good either. Think garden hose vs fire hose. You don't
> always want the fire hose.
>
> also, there's usually signs leading up to engine death by low oil
> pressure unless the pickup falls off or something equally catastrophic.
> The oil pressure gauge reading really really low at idle is one sign -
> but you have to know what normal is to know what too low is.
>
> If you're really concerned, there are oil analysis packages where you
> send them used oil and they tell you what's in it and point to possible
> wear issues.
>
> Or just do what I do - change the oil and filter every three months or
> 3000 miles, and you'll probably never have an internal engine failure.
> (Not including race cars, I've ever only had one major internal engine
> problem - timing gears on my Fiero. Sustained high speed engine
> operation + lousy stock lubrication + plastic gear = failure. But I
> have had 5 transmission failures of all types and 2 mangled diffs,
> mostly due to abuse and old age and buying beaters.)
>

My thouhts exactly. Which is why I hardly paid much attention to the
odd feeling I had about the oil pressure. But I won't be cought by this
problem again. Hopefully.

--
Thank you,


CL Gilbert
"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16

"Steve" > wrote in message
news
> Chas Hurst wrote:
>
>>
>> I would rather have a reliable oil level display.
>
> Every car on the road has one. Its called a "dipstick." Ironically, people
> who don't use that indicator are often called the same thing... ;-)

No ****?
I'm talking about some I can read while seated in the car, we are talking
about gauges here.


> > Low oil pressure is a
>> symptom, not a cause, of engine problems.
>
> Not always. Low oil pressure may be a symptom of worn bearings.
I call worn bearings a problem, what do you call them?

Its also
> an indicator of an oil filter that has collapsed internally, and should be
> replaced. Failure to do so can CAUSE engine damage that could have been
> prevented by reacting to low oil pressure and replacing the $3.00 filter
> instead of a $2500 engine. Its an indiator of a blocked or broken oil
> pickup screen that will starve the engine for oil and destroy it, but
> which is very cheap to fix before any damage is done. Its an indicator
> that the dummies at Jiffy Gloop put 5w20 oil in an engine that needs
> 10w30. And on and on and on.

If any of the above happens while driving, you're screwed. Doesn't matter if
you have a gauge or a light. Talk to the Benz drivers what have the vacuum
pump break and lock the oil pump.

> A low oil pressure warning is FAR more important than a low oil level
> warning when the engine is operating. For one thing, you can have a
> crankcase full of oil, but the engine will still starve for oil and seize
> if the oil pump isn't pressurizing the oil system, if the filter is
> clogged, if the pickup screen is blocked (eg due to a dented oil pan),
> etc. etc. etc. Conversely, and engine will survive being 3 quarts low on
> oil for a time without any damage whatsoever, provided that there's still
> enough oil to submerge the pickup so that it doesn't draw in air (which,
> by the way, will be indicated by the oil pressure gauge).

Oh horse****. It's much more common that the drain plug falls out. The
pressure gauge then tells us that the engine is ruined.

> You need an oil LEVEL indication when doing routine checks (weekly is a
> good idea). You need an oil PRESSURE indication any time the engine is
> running. Big difference.

I know what I need. You don't.

Steve wrote:
> CL (dnoyeB) Gilbert wrote:
>
>> Trying to get some lessons learned from my first car 'death.'
>>
>> To make it short, the oil gauge started behaving curiously to me
>> probably last year this time. But since the oil light didnt come on,
>> and the pressure seemed high enough, nothing seemed wrong. This
>> turned out to be bad because the odd pressure behavior was probably a
>> sign of some engine parts that have to do with oil pressure going bad.
>>
>> So the engine is shot. Loud rapping and knocking etc. And now I can
>> see the oil pressure gauge is doing an extreme version of what it was
>> doing last year. needing higher RPM to sustain higher pressure. I
>> couldn't have recognized it without ever seeing it before.
>>
>> The question is, my new car has only the idiot light. Which of course
>> never lit on my blazer since the oil was actually always there. If my
>> engine parts start to wear out and pressure drops, how will I know it?
>> Or am I out of luck without a gauge. I know the light will light when
>> the pressure is low, but that didnt help the blazer because it was
>> more 'odd' pressure behavior than low pressure.
>
>
>
> I can't help pointing out that a gauge, which WAS indicating a problem,
> didn't stop you from wrecking the last engine by continuing to operate
> it, so why would it matter now?

The pressure was not low. It was only behaving oddly. Its only in
heindsight that I can see what this was about. Which means going
forward it wont happen to me again.

>
> Of course a gauge is far better than an idiot light because once you get
> used to what "normal" behavior is you can observe changes from normal
> that would indicate a clogging oil filter (or one with a collapsed
> element), weak oil pump, too much pressure loss in the engine, etc.
> whereas a light just comes on when the pressure is far too low to
> sustain the engine. But that said, a WHOLE lot of cars on the road have
> "idiot gauges" that don't read true engine oil pressure, but just snap
> up to an "acceptable" zone when a pressure switch closes. The
> manufacturers got tired of unnecessary service calls because so many
> drivers don't understand that oil pressure DOES vary with engine speed,
> engine temperature, oil grade, oil age, filter type, and lots of other
> conditions. Its actually a fairly hard to tell if something is or isn't
> going wrong by looking at an oil pressure gauge on a randomly picked car
> UNLESS you know how that engine's oil pressure behaves normally. Some
> engines are perfectly healthy with 40 PSI of oil pressure at 5000 RPM,
> others would have to be extremely worn to show that little pressure at
> that speed.
>

Yes. I have just learned this since I posted this topic. I had no idea
OEMs were pulling this stunt. Im speechless.

> And as an aside, I still haven't seen conclusive evidence of what really
> went wrong with your blazer engine. You still haven't described what the
> "odd" behavior was.

I can't describe it. it was really a feeling that the pressure was not
normal. Sometimes the needle would vibrate to the feel of the engine
and other subtle things. I would go check my oil, and then be stumped.
But the feeling never went away. Its been to the dealership several
times. I bet if my main mechanic was not renovating he would have
cought that and saved me a bundle. Dealerships are a last resort...

My main mechanic had reopened as it died. He told me how the engine can
start to fail and how that would affect oil pressure. Which would in
turn make it fail even faster. I didnt know that before.

So now any odd behavior of that pressure is going to demand more serious
attention on all of my cars.


--
Thank you,


CL Gilbert
"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16

wrote:

> Worn pumps, or weakened oil pressure regulators in the pumps, can let
> oil pressure drop to extremely low values, as well as the above comments
> by Steve. Occasionally, an oil pump pickup arm will come loose, allowing
> the
> pump to suck air instead of oil. You really don't want that to happen.


Time for an anecdote. I once had a big-block Chrysler engine in a car
that had been in a minor collision. Some of the collateral damage was
that both motor mounts were separated at the rubber "biscuits", and the
engine had impacted the steering gearbox, apparently mildly. OK, fixed
all that stuff, and everything worked fine except "hmm, the oil pressure
sure falls lower than it used to at idle, but its fine at speed." Being
suspicious by nature, I changed the oil and filter, and d*mned if the
thing didn't REFUSE to prime the new oil filter and build any pressure
at all!

Long story short, BB Chryslers have an external oil pump down low on the
driver's side. The cover of the pump (a cast iron piece) has a cast-in
"ridge" that is drilled inside and fitted with the oil pressure
regulator piston and return spring, which when lifted allows oil to
bleed off the output side of the pump and go right back to the input to
limit the net output volume. During the collision, the oil pump cover
had said "hello!" to the engine mount boss on the crossmember right by
the steering gear, which had ever-so-slightly egg-shaped the bore that
the pressure regulator piston ride inside. The first time that the
engine was brought up to speed after the accident repair, the pressure
reguator bound up in the egged bore and hung partially open. Result:
full pressure at high RPM, low pressure at idle, and once air was
allowed to enter the oil pump, not enough suction to draw oil up from
the pan at all. I swapped the oil pump cover with one off another pump,
and everything worked great. Then I changed the whole oil pump (less
than an hour effort since its external- God bless Chrysler engineers of
the late 50s!) and never had any further trouble.

IF I hadn't been suspicious, that car would have had chronic low oil
pressure until the first oil/filter change, and if that hadn't wiped the
bearings, running dry after the oil change sure would have.

CL (dnoyeB) Gilbert wrote:


> My oil levels were almost always appropriate. Even when the engine was
> shot and the pressure was fluctuating low, the oil quantity was still
> appropriate.
>

That was my point.

Chas Hurst wrote:

> "Steve" > wrote in message
> news >
>>Chas Hurst wrote:
>>
>>
>>>I would rather have a reliable oil level display.
>>
>>Every car on the road has one. Its called a "dipstick." Ironically, people
>>who don't use that indicator are often called the same thing... ;-)
>
>
> No ****?

Not here, but apparently there's some in your Cornflakes. Or else you
can't recognize a joke. ;-p

> I'm talking about some I can read while seated in the car, we are talking
> about gauges here.

Its fine to have an oil level gauge in the car. Its not fine to have it
INSTEAD of a pressure gauge. Its not fine to have both and see the
pressure warning, but keep driving because the oil level is fine which
is what many drivers would DO if they had both gauges available. In the
interest of best protecting the engine, the primary warning should come
from the pressure sensor.

>
> Its also
>
>>an indicator of an oil filter that has collapsed internally, and should be
>>replaced. Failure to do so can CAUSE engine damage that could have been
>>prevented by reacting to low oil pressure and replacing the $3.00 filter
>>instead of a $2500 engine. Its an indiator of a blocked or broken oil
>>pickup screen that will starve the engine for oil and destroy it, but
>>which is very cheap to fix before any damage is done. Its an indicator
>>that the dummies at Jiffy Gloop put 5w20 oil in an engine that needs
>>10w30. And on and on and on.
>
>
> If any of the above happens while driving, you're screwed. Doesn't matter if
> you have a gauge or a light.

You're only "screwed" if you keep driving the engine and ignoring the
pressure warning. In fact, that's not even necessarily true. All of
those conditions can LOWER the oil pressure enough that you're warned
that something isn't right without necessarily totally shutting off the
oil flow.

>
>>A low oil pressure warning is FAR more important than a low oil level
>>warning when the engine is operating. For one thing, you can have a
>>crankcase full of oil, but the engine will still starve for oil and seize
>>if the oil pump isn't pressurizing the oil system, if the filter is
>>clogged, if the pickup screen is blocked (eg due to a dented oil pan),
>>etc. etc. etc. Conversely, and engine will survive being 3 quarts low on
>>oil for a time without any damage whatsoever, provided that there's still
>>enough oil to submerge the pickup so that it doesn't draw in air (which,
>>by the way, will be indicated by the oil pressure gauge).
>
>
> Oh horse****. It's much more common that the drain plug falls out.

I've had a couple of occasions where I lost oil *pressure* while
driving (blown-off filter, a broken oil-pump drive shaft on a F*rd).
I've never destroyed an engine by starving it for oil. I've also *NEVER*
lost a crankcase full of oil while driving, nor have I known anyone who
did. In the case of the blown oil filter, an oil level warning would
have occurred a good while AFTER the oil pressure warning because it
would have taken a while for the pump to empty out the crankcase. the
pressure warning was immediate, though.

> The
> pressure gauge then tells us that the engine is ruined.
>

ONLY if you KEEP DRIVING IT. Let's take your scenario- the drain plug
magically pops out while you're driving a car with an oil level warning:
The oil level starts to drop. At some point the oil level warning comes
on, you pull over, everything's fine.

And if the car has a pressure gauge, it indicates a drop in pressure
maybe 10 seconds after the oil level warning would have, and you pull
over, shut down, and you're STILL fine.

>
>>You need an oil LEVEL indication when doing routine checks (weekly is a
>>good idea). You need an oil PRESSURE indication any time the engine is
>>running. Big difference.
>
>
> I know what I need. You don't.

I have a few ideas of what you need. Heavy sedation ranks high on the
list. So does a solid whack with a clue-by-four. And a sense of humor-
sheesh, what'd I ever do to you except disagree and then outline my
reasoning?

No, I take it back. I really don't know what you need, nor do I care. I
do know what a car engine needs to tell a competent driver in order to
avoid being destroyed, though. And oil level isn't top of the list. Its
a harder sensor to implement than a pressure gauge, is redundant with
the dipstick anyway, and is not as good an indicator of impending
oil-starvation damage when compared to an oil pressure gauge.

"Steve" > wrote in message
...
>
>
> Chas Hurst wrote:
>
>> "Steve" > wrote in message
>> news >>
>>>Chas Hurst wrote:
>>>
>>>
>>>>I would rather have a reliable oil level display.
>>>
>>>Every car on the road has one. Its called a "dipstick." Ironically,
>>>people who don't use that indicator are often called the same thing...
>>>;-)
>>
>>
>> No ****?
>
> Not here, but apparently there's some in your Cornflakes. Or else you
> can't recognize a joke. ;-p

I don't eat Cornflakes, but you can put whatever you like on yours.
Jokes are universally recognized as humorous, please try again.

<rest of bull**** snipped>

> No, I take it back. I really don't know what you need, nor do I care. I do
> know what a car engine needs to tell a competent driver in order to avoid
> being destroyed, though. And oil level isn't top of the list. Its a harder
> sensor to implement than a pressure gauge, is redundant with the dipstick
> anyway, and is not as good an indicator of impending oil-starvation damage
> when compared to an oil pressure gauge.

Well, you try checking your oil while you're driving down the interstate. I
think a level gauge will be of more benefit than any (heavily) dampened
gauge you find on a current car. Any car I've ever driven has oil pressure
if it has oil. Go to Grease Monkey or such a few times and get back to us.
Did you know Ford, and by extension Mazda, use a switch, not a transducer,
to drive the pressure gauge?

CL (dnoyeB) Gilbert wrote:
>>
>
> My thouhts exactly. Which is why I hardly paid much attention to the
> odd feeling I had about the oil pressure. But I won't be cought by this
> problem again. Hopefully.
>

which was WHAT?

Chas Hurst wrote:


> I don't eat Cornflakes, but you can put whatever you like on yours.
> Jokes are universally recognized as humorous,

Except by the butt of the joke.


> Well, you try checking your oil while you're driving down the interstate.

Why would an intelligent person do that, rather than when the car is
stopped. If the car has good oil pressure, it has enough oil until the
next stop.

> I think a level gauge will be of more benefit than any (heavily) dampened
> gauge you find on a current car.

Then you think erroneously...

> Any car I've ever driven has oil pressure
> if it has oil.

....and your experience is limited...

> Go to Grease Monkey or such a few times and get back to us.

....and you aint makin' no sense.

> Did you know Ford, and by extension Mazda, use a switch, not a transducer,
> to drive the pressure gauge?

I believe that if you pull up my previous post (before the one you took
to task) you'll find that I made that very point. And someone else
pointed out that BMW does so as well. But even an "idiot gauge" is more
indicative of impending engine damage than an oil level gauge. The
presence of oil in the pan does NOT mean that its going to the right
places inside the engine.