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Bad oil pump? Gauges

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Old 03-27-2016, 01:54 PM
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Default Bad oil pump?

I need some help with my Jeep gang. 99% of the time my engine runs fine, but every once in a while my check gauges light will come on and the oil pressure will go down to 0. After i start it back up i can tell the engine is running without oil for a couple seconds and then it runs fine. I'm no mechanic but i'm suspecting my oil pump is close to failing. Am i correct? Or is there something else going on here? Oil pressure sensor?

Last edited by mattyice; 03-27-2016 at 02:17 PM. Reason: fix
Old 03-27-2016, 04:47 PM
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Our oil pressure gauges are notorious for lying about what's really going on. Before you do anything else, you should verify the oil pressure with a mechanical gauge.

I got a Bosch at the auto parts store for 16 bucks, took all of 10 minutes to hook it up (counting opening the package) and it was well worth it. Since you have an intermittent problem, you could just connect it and run the line into the cab and set it on the dash where you can see it, then drive as usual. That will tell the true story.
Old 03-27-2016, 08:13 PM
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Originally Posted by BlueRidgeMark
Our oil pressure gauges are notorious for lying about what's really going on. Before you do anything else, you should verify the oil pressure with a mechanical gauge.

I got a Bosch at the auto parts store for 16 bucks, took all of 10 minutes to hook it up (counting opening the package) and it was well worth it. Since you have an intermittent problem, you could just connect it and run the line into the cab and set it on the dash where you can see it, then drive as usual. That will tell the true story.
^This, the oil pressure senders are notoriously unreliable on XJs (and many other Chrysler products) and wiring issues are relatively common as well. Check with a mechanical gauge and then replace the sensor if needed (it is also common for oil to leak from he sensor into the electrical connection causing erratic readings, if this is the case it will be obvious when you pull the connector).


As for the noise on start up, what oil filter are you running? Fram (and some other "cheap" filters) have lousy anti-drain-back valves which are known for allowing oil to drain out causing "dry-starts" where the top-end runs without oil for a few seconds until pump can push it up there (especially an issue in cold weather when the oil is thicker).
Old 03-27-2016, 09:05 PM
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Check the pressure with a mechanical & report back.
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