i have 4.0 in my wrangler. the engine is out of a 94 cherokee. it runs great. typically, the oil pressure is a bit low, but over 20 psi. sometimes, (i think it has only done this after being on the highway for a while, then getting off and waiting at a red light), the gauge will show almost no oil pressure and the check gauges light will illuminate. if i just rev the engine, the pressure will jump to 20, then drop as the engine comes back to idle. once i take off, the pressure never drops again, even when idling at a red light. im not too concerned about this, but was curious.
any thoughts?
Low Oil Pressure
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not that i can add much, but my oil pressure gauge has showed no oil at times, and revving it makes the gauge go back to normal. I've read of numerous sender issues online for the motor.
Mine's basically been doing the same things for years ... but if you somehow prevent a catastrophe, let me know!
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Check your oil level. If that is ok you might try a thicker weight oil (if your motor has a lot of miles on it). If thicker oil fixes the problem then you're bearings are wore out and need replacing.
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Its the sensor more then likely I have the same issue.
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There is no issue 4.0l motors will run almost no oil pressure at idle after they warm up and they get a few mles on them. The street jeep has 154k on the clock and it reads 1-2psi at idle.
Aaron
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My old 258 would do this as well. Remember there is a difference between volume and pressure. There is plenty of volume, just the bearings are too loose to build pressure at idle once it warms up. I ran 15w40 rotella in it and it helped a little. Only way to "fix" it is new bearings.
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I know this is going to be wrong but what about a semi clogged oil pan screen. I don't know the real name of it but the screen on the pump sitting in the oil pan. If that gets clogged could that have some affect like this?
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I know this is going to be wrong but what about a semi clogged oil pan screen. I don't know the real name of it but the screen on the pump sitting in the oil pan. If that gets clogged could that have some affect like this?It will, but not at idle. A clogged screen will cause the engine to starve for oil at high rpms when the pump is moving a lot more volume of oil.
Too the OP, I had similar issues with my LJ, turned out the oil pressure sensor was clogging up with gunk and causing low readings. I installed a new one and no more issues.
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I had this on my 258, I replaced my OP, and it did get better but would still be freakishly low at idle.
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Just put duct tale over the gauge and you'll never know its there... easy fix haha...
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my cj7 read 5psi at startup and would drop to 0 under normal operating conditions. the needle would move (1-2psi) above 3kRPM my mechanic said...you can rebuild it, and it will fix it, or run it till it dies, and rebuild it then. 7000 miles without oil pressure later i sold it without a single engine issue (30 miles each way to work when i was driving it)
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Try some thicker oil and throw in some Lucas. Also you might put in a mechanical oil gauge to replace the electrical.
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Nope!! All is lost and you're engine is shot! Time for that Hemi or diesel upgrade!
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Nope!! All is lost and you're engine is shot! Time for that Hemi or diesel upgrade!
...i just put this one in less than a year ago! now, if you want to fund it, then ur on to something, haha
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