Low oil pressure at hot idle

[Redsnake]

I didnt have any other symptoms, no knocking, coolant missing or milky oil. I installed a new sending unit and it seems to have fixed the problem. The check engine light never came on, it was the check gauges light.

Gotcha... I miss-read that one. Glad replacing the Sending Unit took care of the issue.

On my old '96 XJ the oil pressure would bounce all over the place... replaced the sending unit about 3 times over a period of 6 years... and sooner or later the replaced SU would start to fail.

 

[s14unimog]

I know the OP had his question answered but I want to add something. I was having identical symptoms the other day(s); as if I told him what to write in the original post. After double checking the oil level and signs of obvious leaks/issues, I unplugged the sensor, wiped off some of the oil residue and wiggled the plug around while reconnecting it. Sure enough, when I got back in the truck (i did all this while putting gas in) the oil pressure was up to almost 30psi hot idle and running 50-60 at speed. Those sensors seem to be capable of sending false readings if there is a connection issue. I was really surprised b/c I would have thought it would be an all or nothing fault but somehow it just scares the sh*t out of you with a lower reading. Been the same for the last week now.

 

[cruiser54]

I know the OP had his question answered but I want to add something. I was having identical symptoms the other day(s); as if I told him what to write in the original post. After double checking the oil level and signs of obvious leaks/issues, I unplugged the sensor, wiped off some of the oil residue and wiggled the plug around while reconnecting it. Sure enough, when I got back in the truck (i did all this while putting gas in) the oil pressure was up to almost 30psi hot idle and running 50-60 at speed. Those sensors seem to be capable of sending false readings if there is a connection issue. I was really surprised b/c I would have thought it would be an all or nothing fault but somehow it just scares the sh*t out of you with a lower reading. Been the same for the last week now.

Being that the sensor is a variable ground and if that ground through the wire is not good, the reading will be off. My policy is RCBRC: Refresh Connections Before Replacing Components.