Low Oil Pressure

JP13

TJ Enthusiast
Supporting Member
Joined
Nov 11, 2015
Messages
531
Location
Isla Nublar
2005 4.0

Random low oil pressure.
Check gauges light comes on.
No check engine light.

What could be the problem?
 
One of the best ways to confirm your pressure is to remove the oil pressure sensor and install a pressure gauge. I believe the sensor is 1/8 NPT. If you find the sensor is bad stick with the OEM Mopar sensor as the aftermarket sensors are prone to failure.
 
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2005 4.0

Random low oil pressure.
Check gauges light comes on.
No check engine light.

What could be the problem?
The sender causes that problem enough that I would just replace it with a new Mopar sender (no store brands) and not bother installing an aftermarket gauge first.
 
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I'll pass on adding another gauge. I want the OEM to work correctly. I'll replace the sensor. Thanks.
 
I'll pass on adding another gauge. I want the OEM to work correctly. I'll replace the sensor. Thanks.

The point was to install a gauge temporarily just to confirm it's not a pressure problem, not on a permanent basis.
 
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The point was to install a gauge temporarily just to confirm it's not a pressure problem, not on a permanent basis.

Thanks, but I think the money spent on a temp gauge would be better spent on replacing a sensor since my LJ has high mileage.
 
I have the same issue. However, I replaced the sending unit and the Jeep continues to suddenly show a drop to 0 in the oil pressure, then immediately rises to normal pressure. I have a 2003 TJ with the 4.0. Any help would be appreciated.
 
I have the same issue. However, I replaced the sending unit and the Jeep continues to suddenly show a drop to 0 in the oil pressure, then immediately rises to normal pressure. I have a 2003 TJ with the 4.0. Any help would be appreciated.
Did you replace with a Mopar sender? The aftermarket ones are junk. Otherwise, buy a mechanical gauge to check your actual oil pressure.