Oil pressure dropping to less than 20
#1
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Year: 1994
Model: Grand Cherokee
Engine: v8
Oil pressure dropping to less than 20
Time for a new oil pump? Dang thing is running at just over 40 until it gets hot, then it drops to 20 at cruise. Come to idle and the pressure is a little over 15.
I have a new pump on the way, is there something else I should be looking for/at?
The old girl has 223 on the clock.
I have a new pump on the way, is there something else I should be looking for/at?
The old girl has 223 on the clock.
#2
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Year: 2004
Model: Grand Cherokee
Engine: 2000 4.0
Your within spec. What is your idle rpm? What is pressure at 2000rpm? What is engine temperature? What type of oil + filter? It does not sound like you have a problem.
#3
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Year: 1990
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Engine: 4.0
I'd verify the actual pressure with a mechanical gauge before proceeding.
I'm curious also about what brand of oil filter you're currently using.
Pull the wire off the oil sender. Is it oily in there?
I'm curious also about what brand of oil filter you're currently using.
Pull the wire off the oil sender. Is it oily in there?
#4
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Year: 1998
Model: Cherokee
Engine: 4.0 i6
Pull the oil sender off and run a zip tie or pipe cleaner through it. Gunk builds up in there giving you an incorrect reading because as the oil gets hotter and thins out, it looses its ability.to push through the gunk to get to the OPSU. THEN check it with a, mechanical guage.
Odds are, your fine. Min oil pressure spec is 13psi according to the FSM and many other sources. Mine has been running at that for 2 years with no problem. But still do what i said before. Be careful not to mess up the OPSU when removing it to do the pipe cleaner or ziptie, the littlest bump messes them up. I have big hands and i already wrecked 3 when changing my oil
Odds are, your fine. Min oil pressure spec is 13psi according to the FSM and many other sources. Mine has been running at that for 2 years with no problem. But still do what i said before. Be careful not to mess up the OPSU when removing it to do the pipe cleaner or ziptie, the littlest bump messes them up. I have big hands and i already wrecked 3 when changing my oil
#5
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Year: 1994
Model: Grand Cherokee
Engine: v8
I believe that the sending unit is accurate.
I replaced it because I didn't like the reading. and it is reading basically the same. Also, I had that leak around the oil filter adapter and leaked half of my oil out over two weeks. When I went around a corner, the needle hit "zero" and the valves started clattering. Despite replacing the o-rings, the oil pressure does the same 'fade" as the engine hits operating temp.
No clatter, but I suspect a stuck/worn pressure bypass.
Oil is 10/30 like always. Filter is new. Oil is new. this pressure issue is also new.
ETA: The engine runs at 210 always. No oil around the sender, nor under the cap.
I replaced it because I didn't like the reading. and it is reading basically the same. Also, I had that leak around the oil filter adapter and leaked half of my oil out over two weeks. When I went around a corner, the needle hit "zero" and the valves started clattering. Despite replacing the o-rings, the oil pressure does the same 'fade" as the engine hits operating temp.
No clatter, but I suspect a stuck/worn pressure bypass.
Oil is 10/30 like always. Filter is new. Oil is new. this pressure issue is also new.
ETA: The engine runs at 210 always. No oil around the sender, nor under the cap.
Last edited by rangermonroe; 11-15-2013 at 11:27 PM.
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Go to Rotilla 15-40 with a Napa gold, same as Wix) filter, and don't worry about the gauge.
OK, you didn't fill out your info. If you are in Ice, North Dakota that might not be the correct oil.
Last edited by DFlintstone; 11-16-2013 at 05:01 AM.
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#9
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Year: 1990
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What BRAND of oil filter? This only started since an oil change?
#10
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Year: 1994
Model: Grand Cherokee
Engine: v8
No, it didn't start with an oil change.
I have replaced the OPSU as I suspected that it might be the culprit. It reads the same as the old one.
The oil leak around the adapter started at the last oil change, but has been rectified.
The pressure was running steady at 40+/- 5 and then started the wild swinging.
It drops to "gauge" zero after the engine is warm at idle, but hits about 25psig while running.
Despite reading "zero" there is no valve clatter.
I have replaced the OPSU as I suspected that it might be the culprit. It reads the same as the old one.
The oil leak around the adapter started at the last oil change, but has been rectified.
The pressure was running steady at 40+/- 5 and then started the wild swinging.
It drops to "gauge" zero after the engine is warm at idle, but hits about 25psig while running.
Despite reading "zero" there is no valve clatter.
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Year: 1998 Sport
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Since Cruiser has already asked a couple of time and You won't answer the simple question I figured I would give it a try... What brand of filter are you using? Since a crappy filter can make a big difference on your pressure reading. Also have you tried to clean it the hole for the oil sending unit. I'm not talking about on the sending unit but the hole in the block.
#12
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Year: 1990
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Since Cruiser has already asked a couple of time and You won't answer the simple question I figured I would give it a try... What brand of filter are you using? Since a crappy filter can make a big difference on your pressure reading. Also have you tried to clean it the hole for the oil sending unit. I'm not talking about on the sending unit but the hole in the block.
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So many people wanting help but they want to keep things to them self. The small thing like a filter can make a big differance and they can seem to understand that. Or they don't want to verify the pressure. They would rather start throwing parts at it then they wonder why they can't fix it.
#14
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Year: 1990
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We sure are!
So many people wanting help but they want to keep things to them self. The small thing like a filter can make a big differance and they can seem to understand that. Or they don't want to verify the pressure. They would rather start throwing parts at it then they wonder why they can't fix it.
So many people wanting help but they want to keep things to them self. The small thing like a filter can make a big differance and they can seem to understand that. Or they don't want to verify the pressure. They would rather start throwing parts at it then they wonder why they can't fix it.
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Year: 2004
Model: Grand Cherokee
Engine: 2000 4.0
Since Cruiser has already asked a couple of time and You won't answer the simple question I figured I would give it a try... What brand of filter are you using? Since a crappy filter can make a big difference on your pressure reading. Also have you tried to clean it the hole for the oil sending unit. I'm not talking about on the sending unit but the hole in the block.
+1 AGREE. The first step in diagnosing a problem is collecting data. Without data your just another person with an opinion.