wtf no oil pressure

[TheProfessor]

hey guys
my mechanic finished the rebuild on my 3.1
he primed it and was breaking in the cam
the oil pressure was up where it should be for about 5 minutes
and then dropped like a stone
anyone have any idea what the hell could have happened

[88jbody]

Did you use a new oil pump? It's a good idea, I have seen a few of those oil pumps fail.

[TheProfessor]

i have a melling hv pump and its like brand new

[CNCguy]

Check it with a manual gauge... The sending unit failed on my S-10 with a 4.3 within a week of putting in a new long block. I think maybe the higher pressure from the fresh motor caused it to fail. Who knows

[TheProfessor]

im pretty sure he used a manual gauge

[geoffinbc]

Make sure no oil galley plugs have come out. If any did there would be a lot of oil around. Also you may need to drop the pan and make sure the pickup is not touching the bottom, that it is not clogged and that it has not come off the pump body.

[GPXSS]

Pan's gonna have to come off so you can check it.