Is this normal oil pressure while idling?

I

Indiuss

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Just wondering if this is normal oil pressure for when my jeep is idling because I notice when im driving the pressure is around 40 but when i slow down it drops

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Perfectly normal. 10 psi per thousand engine rpms is a good general rule of thumb for acceptable oil pressure. The oil pump is engine driven so the faster/slower the engine rpm the higher/lower the oil pressure.
 
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Oil pressure is tied to heat and viscosity. When oil becomes hot, pressure drops and it should stabilize. When oil is cold and/or has high viscosity, oil pressure increases. Low oil pressure after the engine has reached operating temperature is sometimes indicative of a problem. Very low rpm at idle, low oil level, fuel diluted oil, and a malfunctioning oil pump, are a few things to look at.
 
Totally normal at idle if you have an earlier year TJ (which has a real gauge, not a dummy gauge as is found in later year TJs)

Suggest you download the service manual for your year Jeep. Great info (including acceptable oil pressure readings).

Focus on that check engine light
 
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k-huevo said:
Oil pressure is tied to heat and viscosity. When oil becomes hot, pressure drops and it should stabilize. When oil is cold and/or has high viscosity, oil pressure increases. Low oil pressure after the engine has reached operating temperature is sometimes indicative of a problem. Very low rpm at idle, low oil level, fuel diluted oil, and a malfunctioning oil pump, are a few things to look at.
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Mine was doing this I replaced oil pressure sensor, problem fixed.
 
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k-huevo said:
Oil pressure is tied to heat and viscosity. When oil becomes hot, pressure drops and it should stabilize. When oil is cold and/or has high viscosity, oil pressure increases. Low oil pressure after the engine has reached operating temperature is sometimes indicative of a problem. Very low rpm at idle, low oil level, fuel diluted oil, and a malfunctioning oil pump, are a few things to look at.
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Since the oil pump is engine driven, oil pressure is also directly related to engine RPMs. The higher the engine RPMs the higher the oil pressure. The lower the engine RPMs the lower the oil pressure. The engine RPMs affect oil pressure far more than the oil temperature does. 10 psi per thousand engine rpms is a good rule of thumb for good acceptable oil pressure for our Jeep engines.
 
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Is there any way to convert the late style OP setup to actually reflect reality? I'm assuming it would take a re-flash of some sort...
 
Zorba said:
Is there any way to convert the late style OP setup to actually reflect reality? I'm assuming it would take a re-flash of some sort...
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Certainly not easily, and a different sender wouldn't do it. Even though I grew up with accurate oil pressure gauges I am not bothered by my 04's constant mid-scale oil pressure indicatation. The computer only positions it there if the real underlying oil pressure is where it should be.
 
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Meh - yea, I know. Its the principle of the thing - it might as well be an idiot lite. There'll probably eventually be a cluster of various aftermarket gauges, what's one more? :D
 
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