testing 223 oil pump

Anyone have a good method for testing an oil pump on a 223? Put a drill on a 1/4 inch key, but not getting any oil at the top of the engine... Could something else restrict flow between the pump and the top? (Engine is out of the truck...)

you may need to pack impeller cavity well with grease to insure suction at start up

Hi, Unibody Madness is telling you he thinks the pump lost it's prime and I think so too. It may be very dry. You may have a broken pickup or a clogged screen. I would remove the oil pressure sender and spin the pump with your drill, I believe clockwise, but I am not sure, and see if you get oil at the sender. If you do get decent oil at the sender, it is not the prime. If there is no oil at all, I think you may be able to back prime the pump squirting or pouring a lot of oil down the hex shaft hole (if you're lucky) , or figure out how you can fill the oil passages through the sender opening I have 3 ideas for that. 1 squirt can, 2 gravity, 3 somehow pressurize it. I would screw in regular pipe fittings and pipe adapters until it is big enough and high enough to hold a small funnel, and slowly add some oil. That should prime you pump pretty easily. Good luck

Hi, I need to make a correction to my advice. I was thinking about engine builders priming a motor through the oil pressure mount. This will not prime the pump because of the oil filter. Try to squirt oil in where the filter screws on. I think the hole which is NOT the oil filter mounting goes right to the pump. Good luck

Thanks, guys...

I've got 55 psi at the sending unit, but still not seeing anything up top. Screen is clear.

The block passage is clogged up this was a common problem with these engines back in the day with the old high ash oils and lack of maintenance. They used to have top end oiling kits to fix them sometimes you can find them still, or you will need to pull the rocker assembly and clean all the top end of the head and the oil passage going down into the block. Good luck

Thanks- I'll try to find the kit.

I bet your oil tube (the steel 3/16" tubing) is plugged up. Remove the metal oil tubes that hook to both ends of the camshaft and run a length of aircraft cable through them, using carburetor cleaner as a solvent. I was surprised how plugged up the tubes were in my first engine. Also, the tubing runs down to the side of the block under the cam lifter inspection cover and has a goofy rubber o-ring as it's only method of sealing tight. Check to make sure there's a good seal there otherwise the oil pump may just be dumping oil into the tappet inspection area. That o-ring is probably rock hard or maybe even broken.

Good luck!