Oil Pressure Gauge and Engine death

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?
--
Thank you,


CL Gilbert
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If the bearings are worn and the oil is thin, then the idiot light will come on when idling. By then it is time for an engine rebuild. An oil pressure gauge is the best way to detect worn bearings. You will see a noticeable oil pressure drop long before you have any other symptoms e.g. noise or the idiot light coming on. An oil pressure gauge is the best way to convince you that you should not use 5W20 or 5W30 oil in hot whether, which is probably why most vehicles now don't have oil pressure gauges. Beware of devices (most commonly in Fords) that a salesman will tell you are oil pressure gauges, but in fact are not.
"CL (dnoyeB) Gilbert" wrote:

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Mike Walsh
West Palm Beach, Florida, U.S.A.
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when idling. By then it is time for an engine rebuild. An oil pressure gauge is the best way to detect worn bearings. You will see a noticeable oil pressure drop long before you have any other symptoms e.g. noise or the idiot light coming on. An oil pressure gauge is the best way to convince you that you should not use 5W20 or 5W30 oil in hot whether, which is probably why most vehicles now don't have oil pressure gauges.
Note that a failing oil pump will also tend to have similar symptoms, and it's a lot cheaper to replace an oil pump than an engine.

I am sorry to report that a LOT of companies are doing this, not just Ford. Even companies that really should know better, like BMW. It is absolutely shameful. --scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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I think everyone would counsel the wisdom of a proper oil pressure gauge, CL. It is fairly easy to add an aftermarket one, if you don't mind the appearance of a nonstock installation.
Oil lights are called idiot lights for a good reason. If they are glowing red, you may have no oil pressure at all. It is good to have a gauge to reference the easily visible idiot light to actual pressure.
And I also counsel you to change your oil and filter rather often. It is a very cheap insurance policy. I'm not much on oil analyses, but you can even do that if you wish.
IMHO choose a good quality synthetic or dino oil, as your new car requires. Select a premium filter. Sometimes, but not too often, an OEM filter is the better choice, and they are still relatively cheap.
I change oil at 3000 mile intervals. But I realize I am a LOAF (loveable, anachronistic old fart). In no case would I go above 5000 miles, regardless of when the manufacturer of car or oil says.
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snipped-for-privacy@nospam.nix wrote:

Thanks for the info. I did change at about 5000mi. I think these quick oil change places put on the cheapest oil filters that will fit. I like to help folks keep jobs, but I don't trust these folks anymore really. I'm going to use my regular mechanic, going forward, on my current car. Ill see if I can find an oil pressure gauge and get one added to my car. I use 5w30 standard as that is what blazer calls for. I live in Michigan and it does not get too hot up here typically.
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CL Gilbert
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I would rather have a reliable oil level display. Low oil pressure is a symptom, not a cause, of engine problems.
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Chas Hurst wrote:

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

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.
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Agree 1000%. Oil level doesn't mean a damn thing if the pump cant pick it up and circulate it.
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.
Oil analyses cost money which could be better spent on an oil change and a filter.
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snipped-for-privacy@nospam.nix wrote:

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.
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Steve 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.
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CL Gilbert
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CL (dnoyeB) Gilbert wrote:

That was my point.
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No shit? I'm talking about some I can read while seated in the car, we are talking about gauges here.

I call worn bearings a problem, what do you call them?
Its also

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.

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

I know what I need. You don't.
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Chas Hurst wrote:

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

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.

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.

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.

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.

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.
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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 bullshit snipped>

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?
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Chas Hurst wrote:

Except by the butt of the joke.

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.

Then you think erroneously...

...and your experience is limited...

...and you aint makin' no sense.

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.
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Gosh...is he dense?
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CL (dnoyeB) Gilbert wrote:

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.)
The wife's Beretta has 226,000km on the original 3.1 and still has perfect oil pressure. My buddy's Celebrity made it over 300,000km before starting to knock (the oil pressure gauge would blink at idle for months) and the rest of the car was rusted out so he got rid of it...
Oh, and you do know that if you stopped driving it and pulled the engine, you could probably replace the engine and/or rebuild it... it's only when a rod comes through the side of the block is it totally finished. Or the cam comes out the back of the block in 4 pieces... (or both on the same engine.... :)
Ray
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news 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.
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CL Gilbert
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CL (dnoyeB) Gilbert wrote:

which was WHAT?
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CL (dnoyeB) Gilbert wrote:

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?
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.
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.
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