have not checked the gauge yet.....

was working fine untill this morning (about 15 miles from home) ...

ding..ding..ding... oil pressure 0

turned truck off needle went down to 1/8" below 0, restarted and needle went to 0

????

 

Do you have oil in it? Does the engine sound just EXACTLY like it used to? If the answer to both is yes then I would say the sending unit gave up the ghost. Check the plug that is on the sending unit just because it might be loose or even fell off.
Tom

 

1 quart low (due for oil change)
sounds same

checked it again at lunch and pressure holding @ 50#

thinking the sending unit ($70 from cummings right ?)

thanks

 

well it looks like when the truck warms up the pressure drops to 0

could this still be the sender ???

 

Entirely possible. Mine would do fine cold but go nuts when warm. Look at this thread: Sending Unit Info
Tom

 

check oil pressure with a mechanical guage, there may be something in the oil pan being sucked up onto the pump screen after driving awhile. when you shut engine off it falls back down, then you start it and you have momentary pressure. sometimes oil pan gasket gets in there after it breaks off the edge.

 

Put a mech gauge on it. If that shows fine then my first check would be wires. when they get warm they get softer and if there is a open wire somewhere it could possible be grounding out.
My fuel guage just did the same thing. Did you know you can sit under your truck and get your whole head and shoulders up into between the frame and body to reach over the frame and access the tank sender, can't take it out but you can pull the plug to clean it The problem wasn't the tank plug, it was the one in the fenderwell behind the drivers front wheel.