No Oil Pressure

[borahshadow]

This evening I finally got my 5.3 to the point where I was ready to test fire it. I disconnected the coil packs and pulled the fuel pump relay then went and turned the key. No oil pressure. Cranked it for a bit then stopped. Did this a few times and started to get a little nervous. I ended up pulling the oil pressure sending unit and cranking on it to watch for oil squirting out and nothing came. I poured a couple of cups of oil down the oil pressure sending unit's hole to try to help prime the pump and still nothing. I pulled the filter and there was hardly any oil down in there (yeah I realize now that I probably should have filled it before I put it on the first time) I think what was there might have just been from pouring oil down the pressure sender tube. I filled the filter up and cranked it a couple of times for about 10-15 seconds each and still nothing. I hate to just keep cranking on it if it's dry though. Tomorrow I'll call around and see if there is any place where I can rent one of those fancy pressurized pre oiler things.

For the record this motor is completely stock. I got it from junk yard. The deepest I got into the motor was putting in a new rear main seal. I didn't pull the oil pan or anything so I highly doubt that the pickup tube isn't seated correctly.

Ideas?

 

[woody31]

I don't think they prime like a normal small block..I would put it all together and fire it up..good luck.

 

[98_k1500]

The oil pump is on the front of these engines. It is driven directly from the crankshaft. No way to turn it but by turning the crank. Fire it up, It'll prime in a few seconds.

 

[bluex]

Over fill it with oil. I went through this with a 3.8 in a firebird. The oil pump is the front like an ls, after putting about 10 qts in it finally primed an got pressure. Your only other option is one of those pressurized things or pulling the pump out an packing it with Vaseline...

After you get pressure drain the extra oil of course

 

[98_k1500]

yea, if you had a evac canister, you could fill it with clean oil, set it to push instead of pull, and push oil into the oil pressure sending unit hole unitl you fill the pump with it. (probably take a quart if the filter was full)

 

[borahshadow]

Thanks for the suggestions everyone. I didn't quite have the guts to just start it up but what I did do was I pulled out the spark plugs so that the starter could turn it easier and faster. With the plugs out it turned at least twice as fast and within 30 seconds of cranking oil came up through the sending unit hole. I put the sending unit back on and cranked it for another 10 seconds and i had pressure on the gauge. Put my plugs back in, connected my coil packs, reinserted the fuel pump relay and it roared to life on the first try. It was reading about 70lbs of pressure so I've definitely got some oil flowing. Now I just have to button everything up and hopefully find time to post up a build log.