How do oil pumps work?

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As far as how they are driven? Are they electric or are the directly powered by the engine itself? Situation...when you turn the key does the pump start moving at its normal pace electrically or does it turn in proportion to the engine revolutions (driven by the engine itself). Hope this makes since. If its electric, as soon as you turn the key to start it should be pumping oil at full power, if its driven by the engine, you have to wait for the engine to fire up for the oil pump to be fully operational.
 

gregk24

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So what is the typical lifespan of these things with severe service? Doesnt seem like there is much to wear out.
 
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Ohio
Originally Posted By: 901Memphis
Driven by gear off the crank.
+2 So its engine speed dependent, so it will only run when the engine is running, I wouldn't try to concern myself with the fact that it doesn't start turning before the engine does. You have residual oil left on parts, plus anti wear additives.
 
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They used to be driven off the camshaft. a 1988 Oldsmobile tech4 cylinder engine is the first one we had that was driven off the crank(by a gear in the middle of crankshaft), , it even had counter balancer weights in the pump and had to be synchronized.
 
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Southeastern, PA
Driven by the engine, you wouldn't want it any other way. If it was driven by an electric motor, when the electric motor died there goes your lubrication. As far as wear goes, it's probably the most lubricated part in the engine. An important part in the lubrication system is the pressure relief valve. It acts like a maximum pressure regulator. The oil pump is a positive displacement pump. That means it's going to pump oil no matter what. Once the oil pressure reaches the set point of the pressure relief valve, the valve opens. This keeps the lubrication system from over-pressurizing and bad things (like the oil filter bursting) from happening. Just a few thoughts.
 

gregk24

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So if this is the case, why do some say that some car companies have weak oil pumps? Kia, Hyundai, Honda, Toyota etc. If they are driven by the engine then this should not be a problem.
 
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gregk24

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Originally Posted By: Eddie
Who is this "some say"? I never heard that the above manufactures had weak oil pumps.
Just from people commenting on here, thus the reason why the Asian makes use a low efficiency filter. And why Hyundai/Kia have ticking problems with other filters.
 
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Illinois
There usually are high volume or high pressure pumps. The Asian pumps tend to be high volume but lower in peak pressure. At least the ones I have had, Mazda, Yamaha, Hyundai. The Hyundai OEM filter has a 20 psid spec, this would I assume, point to a high flow rate pump. My Genesis Coupe 2L maxes out pressure at 80 psi.
 

Bud_One

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Originally Posted By: expat
I would say, typically, the life of the engine.
There are the few that fail prematurely... The oil pump built in bypass valve would stick in bypass mode intermittently , on my Chevy 6.0 and would cause a lifter tick when driving at freeway speeds.
 
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I've wondered how much shearing of oil is actually done by the oil pump itself, and how much the oil pump by itself heats up the oil.
Depends on the engine. For instance, the Ford / Navistar 7.3 with HEUI is murder on oil and shears it quicker than most pumps. Some pumps are easy on oil, but things like stiff valve springs and flat tappets will shear oil faster than an oil pump ever could.
 
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Silicon Valley
Originally Posted By: Rick in PA
Driven by the engine, you wouldn't want it any other way. If it was driven by an electric motor, when the electric motor died there goes your lubrication.
Ah, if you use an electric pump that has sensor to monitor the motor movement, flow or pressure, then it should be safe enough to cut off the engine if the oil pump died. The pump speed and volume need is not linear to the engine rpm or load, so having a pump large enough for idle or red line will just waste a lot of energy and hp for the opposite end.
 
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Interesting. What sort of pumps are they, in cars? Piston pumps? What are some example cars which use a variable-displacement oil pump?
 
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Sunny Florida
Originally Posted By: bulwnkl
Interesting. What sort of pumps are they, in cars? Piston pumps? What are some example cars which use a variable-displacement oil pump?
A quick one or two: Chevrolet Ecotec, Chrysler Pentastar. There's more, and a lot more coming as mfgrs explore every option to save fuel.
 
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