william_b_noble

there is one other thing that in theory would work - I haven't tried this - if you pull the oil filter and pressurize the crank case to 5 or 10 PSI, you should have enough pressure to push the oil up the pickup tube, through the pump and into the filter housing - the crankcase should be tight enough that it doesn't take a lot of air to maintain 5 psi. This could be worth a try. Alternatively, removing the pressure relief valve and drawing a vacuum should suck oil up through the pump. You may want to try one or the other of these methods.

Van

Yes, if you pull off the oil filter, and pressurize the dipstick tube, you *may* see oil in the outside of the filter housing - but the pump will have to be turning (cranking over) since it is a positive-displacement pump, meaning the gears have to turn for oil to get through it - and your OPRV isn't stuck open.

V2Rocket

has anyone considered the SBC trick, of finding a spare SBC oil pump, a bucket with oil, some hoses and a connection to the pressure-side of the oil system, using a drill to spin the pump to prime the engine before ever cranking it over?

kevin12973

Remember what Van said, fluid will not pass the oil pump unless its turning. Even cranking on the pulley with a ratchet. And if one wants to pressurize the crankcase, remember to pinch off the hose that goes from the oil separator to intake manifold. I tried that trick but didn't work for me.

johntorg

I thought I'd resurrect this thread, since I still haven't found the problem. I did find this post from the PO on 944online.

http://www.944online.com/cgi-bin/for...1931;start=0#0

"This stuff is done:
sealed the pump to the block with loctite 574
new o ring on pickup tube
cleaned pickup screen
OPRV is aligned carefully and exactly and torqued
crank pulley torqued to 155 ft/lbs
The green o ring on the thrust washer is installed
The oil pump and the new-used block match years and part numbers.


Here's what I have tried with no success to prime the pump:

Oil in the center hole of where the oil filter screws on, spark plugs out, run the starter, repeat (2-3 hours of this)

Shop vac on the OPRV hole until oil comes out, spark plugs out, run the starter, repeat (many hours of this) Also tried pumping oil into the OPRV hole, with no success.

Air through the dipstick tube, run the starter no spark plugs. Interestingly enough, this method only produced air coming out of the intake manifold. I'm not sure what that means for the engine, but I've checked it many times, and the air comes right out of the rubber J-bend. There are brand new gaskets and seals from top to bottom of the engine, so I wonder if my piston rings are shot? Anyone have any insight on that?"

The only things that I see that I see wrong are that he didn't pinch off the tube between the Air/oil separator and the intake and he poured oil in the center, not the outside of the oil filter housing.

I will try both of them and see what happens. Anyone have other ideas?

Van

If you did this until oil came out, then you have "primed" the pump... Meaning oil has made it from the oil pan, through the oil pickup tube, through the oil passage way in the girdle, and through the oil pump.

If that is the case, then it's pretty easy to pinpoint the problem to the oil pump - meaning, there isn't a breech in the oil pickup tube or girdle passage, because the suction from the shop vac makes it all the way through. Either the pump is not turning, the pump is missing an internal gear, or the pump has some clearance/space issue internally that prevent the gears from making suction.

kevin12973

The center hole under the oil filter does not go to the oil pump. It's the outside squarish shape hole that leads to the cooler then the pump. You need to prime from this one. The center hole goes to the oil gallies through the block and so on.

johntorg

Thanks, for the insight. I will try both methods. I have tried sucking oil out of the hole for the OPRV and did manage to get some to flow. The pump was good in the original engine also an 84. I have another pump, but its from an 86 and a different part number.

VaSteve

How did you resolve this?