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odd oil pressure

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Old 12-19-2012, 07:40 PM
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Last night I did some light wheeling mostly in sand but a little in some puddles. Didn't get stuck and went through them pretty quickly. Then I started feeling this odd vibration which I couldn't tell if it was my engine or my exhaust or driveline. It was doing it while idling. Still does it if idling for about a minute or so. Anyway today I'm driving and I notice my oil pressure is about 30 idle and 50 just driving slow. It may not be all that high but its normally 20 idle and 40 slow driving so I dont want to ignore 10 more random psi. Then it kinda went really weird and sat at 40 for a bit while idling and barely moved up when driving. I know the sensor on these things is weird but just wondering, how do I check to make sure my oil is flowing correctly and not clogged so I know if its my sensor or a clog somewhere?
Old 12-19-2012, 07:50 PM
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The oil pressure sending unit is a very common failure on the Jeep 4.0. When they fail, they often fail with "higher than normal" readings.

It is located directly above the oil filter. You can verify your oil pressure reading if you want with a mechanical gauge, but most guys just swap in a new sending unit.

If you buy one, I recommend you get a Mopar unit directly from Jeep. Well worth the extra money in reliability/accuracy/mating with your factory gauge.
Old 12-19-2012, 07:54 PM
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Cool sounds good. But also just in case, how do you know if theres a clog somewhere?
Old 12-19-2012, 08:11 PM
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Take a peek under the oil fill cap and see if the rockers are getting oil. That's a pretty good indicator oil is going where it is supposed to. Sudden high oil pressure could indicate an obstruction somewhere, but it's most likely the sending unit. Screw in a mechanical gauge and see what your pressure really is.
Old 12-19-2012, 08:21 PM
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you guys are awesome!
Old 12-19-2012, 08:32 PM
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What oil filter are you using?
Old 12-19-2012, 08:33 PM
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ahh i was hoping no one would ask. good ol fram haha.
Old 12-19-2012, 10:10 PM
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Originally Posted by crimsondragon
What oil filter are you using?

Clogged filter will LOWER pressure not raise it.
Old 12-20-2012, 05:40 AM
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Originally Posted by mattphillips90
ahh i was hoping no one would ask. good ol fram haha.
If you value your Jeep, ditch that Fram crap. Wix, Napa Gold, Mopar are all easily available and worth the extra 50 cents for sure.
Old 12-20-2012, 02:34 PM
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I know I know. I just got it for the oil deal but I'll never use it again. Im gonna change the oil tomorrow now
Old 12-20-2012, 03:45 PM
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Originally Posted by mattphillips90
I know I know. I just got it for the oil deal but I'll never use it again. Im gonna change the oil tomorrow now
Just change the filter. Don't waste any more money on oil.
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