Low oil pressure after engine is hot

[ChasUGC]

I had what seems like a Christmas tree’s worth of lights come on the dash when my oil sender acted up. The engine rough idled and then worked normal again as if it never happened after I shut off the engine and restarted it a few minutes later. A new Mopar sender solved the issue for me.

I had good luck with Valvoline synthetic blend and full synthetic using a Wix xp, mopar, and mobil filter.

Many of us have lifter noise and don’t need a rebuild. Some guys have had lifter noise for many thousands of miles and their tractor engine just keeps on doing what it does.

I had good luck with removing lifter tick (only happened on startups for me) by adding MMO (marvel mystery oil) in with my oil.

I’m too afraid to run MMO with the turbo so I’m running Redline now days for different reasons.

Yeah, it happened to me today as it was a hot day. I got off the freeway and my oil pressure gauge dropped to zero at the stop light. But, my Jeep didn't start to idle rough at all. It didn't stagger at acceleration either, with my AC on. For now, i will change my oil to the Castrol High Mileage Synthetic Blend, and I will add a good anti drain back valve Oil Filter. My mechanic says that my Jeep has the Oil Filter mounted Horizontally, which can cause an issue with back draining of the oil filter. My mechanic is going to test my Jeep in the morning when it makes all the noise, and I will ask him whether the low pressure is a oil sending unit issue. If he replaces the Oil Pressure Sending Unit, and I still have the issue, I will consider getting a Mopar Sending Unit, unless he believes I have an oil Pump issue. I must protect my engine. I really can't afford a new engine right now, if I can avoid it. Thanks for the feedback. Cheers.

 

[Frankm]

I d put a mechanical oil pressure gauge on it and find out if you do have oil pressure when hot, idling. I d screw around with the sensor and wiring AFTER I KNEW it was ok and just a faulty gauge/sensor/wiring.

I would not want to spin a bearing or screw something up while I was fooling around with the earlier mentioned possibilities. Just my thoughts …

 

[TLT1964]

I d put a mechanical oil pressure gauge on it and find out if you do have oil pressure when hot, idling. I d screw around with the sensor and wiring AFTER I KNEW it was ok and just a faulty gauge/sensor/wiring.

I would not want to spin a bearing or screw something up while I was fooling around with the earlier mentioned possibilities. Just my thoughts …

My 97 did the same, sensor wasn't bad, gauge was. Mounted gauge from auto parts at bottom of my dash right below rear wiper and other switches. Got great pressure readings all the time now.

 

[Leebo24]

Good evening. Brand new to the forum. Hoping to get some help. Bought 2005 Rubicon about a year ago. 129K miles. 4.0 L inline 6 motor. Six speed manual transmission. Runs great. Just last night, oil pressure gauge dropped to zero at idle. This occurred after running down the highway for 25-30 minutes at 65 MPH. Motor did not run rough or show any signs of an issue. Jeep ran perfectly the entire trip. As I pulled away from red light and increased RPM’s gauge went back to normal. Next time I stopped, gauge did the same thing. I tapped the throttle, the gauge went back to normal, but quickly dropped to zero again as I let motor idle. No sign of an oil leak anywhere. Let Jeep sit for about an hour and a half. Gauge acted normal. Ran down highway again … low pressure again. Any help would be appreciated. I hear possibly oil pressure sending unit needs replaced. I know oil pressure is going to fluctuate, but gauge moved very little at stops prior to
this.

Thanks in advance. Will post pictures once I figure out how to do so.

After some digging by local Jeep shop, replaced the oil pump drive assembly. Teeth on gears were definitely worn. Drove Jeep 40 miles today, oil pressure gauge was perfect. Oil pressure was good entire trip. Fingers crossed, issue has been fixed. Thanks to everyone who gave ideas and suggestions. Hope this may help another person with similar circumstances.