It's could be a bad pump but that is normally unlikely. Did you
replace it as part of the rebuild? Typically that is part of a
rebuild. Oil pumps are simple mechanical devices so they don't usually
go bad. One problem can be that a piece of crud gets caught in the
relief valve and holds it open. The other possibility and most likely
is that one of the oil passageways in the block was not closed back up
during the rebuild. Normally you removes passageway plugs before the
block gets machined and tanked so it gets as clean as possible.
Sometimes leaving one out can result in all the oil just running right
back into the pan.

If you crank it for a second with the oil filter off and a bucket under
it you could get an idea if the oil pump is doing anything at all. If
oil comes out I'd put my finger over the hole and try it again to see
if it's got any pressure at all. Messy but something to try before you
tear it down.

I would really try to not run it at all until you figure it out.
Bearing wear is very rapid without oil pressure.


wrote:
Thanks for the response. My mechanic has already put his gauge to it
and confirms
no oil pressure. Could there be a bad pump, or some other
explanation?



jamesgangnc wrote:
Put a mechanical gauge on it and make sure it's not a gauge problem.
Don't run it any more until you know. It won't make any unusual noise
until the bearings are shot and then you get to rebuild it again.

wrote:
I have a recently rebuilt Unversal 5418 two-cylinder diesel. My
mechanic started the boat last weekend and noticed there was no oil
pressure. The engine runs and sounds just fine.
Has anyone ever had this problem? Any experience ? Should I curl
up in the fetal position? I just spent 4,000 to have this engine
rebuilt.