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Oil pressure drops as jeep warms up

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Old Jan 14, 2011 | 06:26 PM
  #31  
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Originally Posted by Tomxj48
the sound im talking about you can here when the engine is idleing so I guess.... dude all I can tell you is please for your own sake dont do a ton of useless work...
thats why im on the forum, i never use this but the nois is driving me crazy, dont like driving it when its rattling or when the oil presure gets low, because when i drive it for like 40 miles, then stop at a light its sluggish like it barely wants to get moving again when the oil pressure is down to almost nothing. i know there is absolutly some kind of problem but i dont know exactly what it is, but im bouts to just got to work at it, change the pump the bearings everything this weekend i guess
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Old Jan 14, 2011 | 08:32 PM
  #32  
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Originally Posted by jesse jay
right now im running 10w-40 in it and when it was snowing and like 25 dagrees the other day the oil pressure was down to 5 or less, and it didnt drop so low when i first got it
Factory oil pressure gauges are notorious for being less than accurate. Get a real oil pressure gauge on it and check. It you oil pressure were that low you should feel the engine running rough not just hear it. It could just be a bad sensor.
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Old Jan 15, 2011 | 01:20 AM
  #33  
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Originally Posted by No4x4Yet
Factory oil pressure gauges are notorious for being less than accurate. Get a real oil pressure gauge on it and check. It you oil pressure were that low you should feel the engine running rough not just hear it. It could just be a bad sensor.
nah man thats the thing tho, i can feel it runing funny, like its sluggish from a stop and its chopy when i acelerate from a stop, i can hear and feel the difference so i know the gage is right
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Old Jan 15, 2011 | 01:23 AM
  #34  
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Default Warmer it gets the lower the oil pressure

I have an 89 Cherokee with a 4.0 inline 6, when its cold ill start it up and the oil pressure will be where its supposed to be at 45 but as it warms up the oil pressure drops till it hits like 5 to 10 or even lower the farther I drive, when I give it gas it goes up to maybe 20 but when I come to a stop it idles around 5. the engine will rattle too, only when the oil pressure is down that low when its cold it sounds like a champ, or even when its warm and the oil pressure is low, and I step on the gas it wont rattle. what could the problem be?
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Old Jan 15, 2011 | 01:26 AM
  #35  
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How many miles do you have? That seems like awfully low pressure, mine at idle when its cold is around 60-70 and driving at 80. Once it warms up its more like 40 idle and 60 while driving.
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Old Jan 15, 2011 | 01:27 AM
  #36  
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You have another thread.. use it
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Old Jan 15, 2011 | 01:28 AM
  #37  
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Originally Posted by mrfajita
How many miles do you have? That seems like awfully low pressure, mine at idle when its cold is around 60-70 and driving at 80. Once it warms up its more like 40 idle and 60 while driving.
194000 miles, but my gage only gose up to 80 it should be that high
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Old Jan 15, 2011 | 01:31 AM
  #38  
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Looking through your other thread, this makes me seem like I'm the one with the problem. People saying low oil press is the norm?
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Old Jan 15, 2011 | 01:36 AM
  #39  
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yeah i dont even think that right tho, like yeah you have extreemly high oil presure but its not supossed to drop down to ten ever. its bad haha all the machanics i talk to say that it should run 30 maybe 25 20 at the lowes at idal when its hot, so i don know
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Old Jan 15, 2011 | 01:44 AM
  #40  
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I run at 40-42 ALWAYS no matter what (supposedly, as the gauge says)...idle, driving, flooring it...seems kind of odd to me.
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Old Jan 15, 2011 | 01:45 AM
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Originally Posted by dbcox
Before you spend money on a pump drop the oil pan and check a couple of rod bearings. see how worn they are. If you get a new set of bearings plastiguage then to see what you clearances are. if it its rattling some that may by you some time. you got to drop the pan anyway. bearings arent that much. May save you from dropping the pan twice anyway.
how will i know that the bearings are worn?
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Old Jan 15, 2011 | 02:00 AM
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Originally Posted by jesse jay
I have an 89 Cherokee with a 4.0 inline 6, when its cold ill start it up and the oil pressure will be where its supposed to be at 45 but as it warms up the oil pressure drops till it hits like 5 to 10 or even lower the farther I drive, when I give it gas it goes up to maybe 20 but when I come to a stop it idles around 5. the engine will rattle too, only when the oil pressure is down that low when its cold it sounds like a champ, or even when its warm and the oil pressure is low, and I step on the gas it wont rattle. what could the problem be?
That is low. Lowest it should ever be is 15 according to the manuel. When was the last oil change
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Old Jan 15, 2011 | 02:17 AM
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I would look at your main crank bearings. If the motor has never been rebuilt then they could be worn out. I think the rattling is metal on metal contact being made, though not 100% on that. Are you burning oil out the exhaust at all?
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Old Jan 15, 2011 | 02:44 AM
  #44  
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Originally Posted by 90xj-
I would look at your main crank bearings. If the motor has never been rebuilt then they could be worn out. I think the rattling is metal on metal contact being made, though not 100% on that. Are you burning oil out the exhaust at all?
not burning oil out the exaust but i do lose a good amount of oil, and i can get the the main bearings jus by taking the oil pan off right?
im thinkin replace the main crank bearings and the rod bearings and i got a new pump to put in it already.
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Old Jan 15, 2011 | 02:46 AM
  #45  
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Originally Posted by sycoglitch
That is low. Lowest it should ever be is 15 according to the manuel. When was the last oil change
just changed it like a month ago, i out 10w-40 in it and the rattle got better but not the oil pressure. rattles not gone but its not as bad.
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