Hello. I just finished complete rebuild all new parts. prime pump like it said in manual. started her up after 30 sec. or so oil psi goes from 40 to 0 any ideas? Oh yeah by the way its a 1999 dodge ram 1500

 

welcome to df. repost over in the 2nd gen ram section. nobody will see it over here.

does oil pressure come back if you restart it. if not, sounds like something bad happened to the oil pump shaft or body, or maybe the sending unit. i've heard of oil pump bodys cracking if they're in wrong or ****-eyed.

 

yes if i turn it off and restart it comes back for 30 sec then goes away again

 

deleted... moved.

 

I will move to the second generation Ram section,
FF

 

make sure the oil pick up isn't obstructed in any way.

 

+1 on that

A guy i work with has a Ram 2500 5.7 Hemi, and his motor blew (under warentee) took it in, and they put a brand new motor in it. hes put about 500 miles on the truck, now no oil pressure. he took it in again and said they had to replace the oil pump, even though in the new motor they had a new oil pump put in it. and still it showed damage somehow

So sounds like the oil pump could have let go even though its new, but like he said, cold have gone in ****-eyed

 

Change the oil filter.It's probably a Fram.

 

hmmm is it possible to remove oil pan in the truck? Its def. not a fram. why would i have pressure for 30 sec then lose it but shut it off and restart her and i got 40psi again then lose it after 30 sec? maybe it is the oil pump and the relief valve is sticking wide open.

 

oil filter could be collapsing under pressure. only $4 to find out.
also much easier than dropping oil pan..

my 01 oil pan wouldn't come off until i unhooked it from the flex plate lip,
which required removal of flex plate and starter. pita.
also remove engine to transmission braces.
after all that, my oil pan dropped out ok. i didn't have to remove any exhaust pipes nor lift the engine.