Do I need to prime the oil pump first ?

It's standard practice to fill them with a light grease or vasoline when you install them to help it prime quicker. Since you probably don't want to do that now, I'd remove the spark plugs and spin it with the starter to see if you can get some pressure. If that doesn't work I'd remove the oil sender and pump some oil the galley. Did you change the filter? You might want to pre-fill it if you did.

Good idea..

Normally I spin the engine over with no filter till oil comes out, then install the filter and spin till I see oil pressure. Remove the spark plugs and it spins MUCH faster!

Nope.

NEVER seen a bad oil pump on a nissan in 30 years of working on them as a professional.

Yes.

: > Then after I installed it, a thought occured to me, that thing : > is fulla air and probably won't develop enough negative pressure : > to suck the oil. : >

: > So I very caustiously started the motor and killed it after : > ten seconds when the oil light didn't go out. : >

: > I'm guessing it might need to be primed with oil first? : >

: > If so, will I need to remove it to do this, or will some oil : > find it's way into the pump if I pour some into the fill hole : > on the valve cover ? : >

: >

: >

: > On a side note, a shop had already replaced the bad stuff : > that usually goes wrong with the timing chain guides and tensioner. : > But, after we got it back, sometimes the oil light would come on : > and the performance would drop. : >

: > The original mechanics told me that there was a pressure : > regulating bypass valve in the oil pump that was probably sticking. : > Based on their advice I bought the new oil pump. : >

: > Yet, a buddy of mine told me that sometimes when people : > work on the timing chains, they goop on too much gasket : > compound and block some of the oil passages. : > Does this sound reasonable? : >

: > Interestingly enough, after I finished inatalling the oil pump, : > I noticed a small rubber part laying on thte ground. : > Oh crap I thought, I left some part out, but after I picked : > up the "forgotten" part and inspected it, I noticed that : > it was a sort of silicone rubber plug and it looked to be : > very close to the size of one of the oil passages. : >

: > It's really looking like perhaps my buddy may well have : > made the right call. : >

: > Thanks for any advice : > --Dave Moore-- : >

: >

: : It's standard practice to fill them with a light grease or vasoline when : you install them to help it prime quicker. Since you probably don't want : to do that now, I'd remove the spark plugs and spin it with the starter : to see if you can get some pressure. If that doesn't work I'd remove the : oil sender and pump some oil the galley. Did you change the filter? You : might want to pre-fill it if you did.

No, though I have a new one to put in, I didn't change the oil filter exactly for that reason, I thought perhaps there might be an advantage to having the old one in there with some residual oil in it.

Thanks for the advice

Thanks for the feedback Steve.

-- Dave---

: > So I very caustiously started the motor and killed it after : > ten seconds when the oil light didn't go out. : : Good idea.. : : >

: > I'm guessing it might need to be primed with oil first? : : Normally I spin the engine over with no filter till oil comes out, then : install the filter and spin till I see oil pressure. Remove the spark plugs : and it spins MUCH faster! : : >

: > If so, will I need to remove it to do this, or will some oil : > find it's way into the pump if I pour some into the fill hole : > on the valve cover ? : >

: >

: : Nope. : : >

: > The original mechanics told me that there was a pressure : > regulating bypass valve in the oil pump that was probably sticking. : > Based on their advice I bought the new oil pump. : : : NEVER seen a bad oil pump on a nissan in 30 years of working on them as a : professional. : : >

: > Yet, a buddy of mine told me that sometimes when people : > work on the timing chains, they goop on too much gasket : > compound and block some of the oil passages. : > Does this sound reasonable? : : Yes. : : : : -- : : Steve : :

As detailed earlier, the oil pump should have been packed with vaseline to help the oil pump prime.

Thats whats under the cap on the oil pump body. Typically you would need a BIG piece of crud to plug up the plunger or keep it from sealing.

Happens quite often. If the silicone oozws out when you bolt up a part, you are using too much! Its oozing on the inside too and those "worms" travel well through an oil pump, but frequently get stuck in passageways and orfices.

You might be able to get away with not re-installing it, but to let you know its the seal between the oil pump output and the block. It could start leaking later.

Have fun!

-Pete