blackbyrd

iTrader: (14)

story is its a fresh motor and we were cranking bring it to pressure so we could fire it up and we never could get oil pressure?? what gives we cranked on it for an hour and never got pressure, did i miss something help me out guys

racecar

Yes, you missed the 5/8" freeze plug that needs to be pressed into the front of the block next to the oil pump, or the plastic barbell in the oil galley right above the filter, or the O ring on the oil pickup tube got pinched, or the pickup is sitting on the bottom of the oil pan.

Deeavi

iTrader: (16)

I just finished my new engine, and I have done several LS engines for oil pumps, cams, etc. I have never cranked an engine over to get oil pressure. I just fired it up and the pressure came up. I don't know if cranking one over is going to build pressure. If you built it right with good assembly lube running it for a few seconds is not going to hurt it. If the pressure does not come up after inital start up, then you are going to have to go back into it.

Always check and double check everything and make sure you have the correct new oil pump pickup o-ring.

Good Luck!

racecar

Cranking it with the starter should make good pressure. Take the spark plugs out and crank it.

speedracer5532

iTrader: (8)

I just built my LSX 427 and the same case, couldn't get oil pressure. I knew 100% sure I put the 5/8th freeze plug in the front of the block and the barbell plug in the rear of the block. So I pulled my oil pan and took the pickup tube off. The o-ring looked good but I am sure there was some issue with the o-ring on the tube not sealing. I say 99% of the time a LS engine has no oil pressure it is the o-ring on the pickup tube. I put it all back together and left the oil filter with no oil in it and cranked it over with the plugs out for about 2 10 sec intervals. Went to take the oil filter off to see if there was oil there and there was, so I knew now my pump was pumping. I put the plugs back in and fired it up and had oil pressure right away.

DrkPhx

iTrader: (15)

That's a good point. I always install the oil pump without the front cover and gears so I can see if the o-ring is seated correctly.

blackbyrd

iTrader: (14)

i didnt assemble the engine and it came with the front cover and pulley on it and i didnt know about the barbell plug in the rear i would like to think they would have put those in during assembly, but that company is out of business now so what do i know. i did how ever put the pan and pick up tube on so i will check those before i pull my motor out. thanks guys.

blackbyrd

iTrader: (14)

rear cover has to come off for the barbell doesnt it, and does the front cover need to come off for the other next to the pump

speedracer5532

iTrader: (8)

yes both covers have to come off to check to make sure both of those plugs are in.

blackbyrd

iTrader: (14)

also we filled the oil filter and after we cranked it a few times we undid the oil filter and it over flowed so that mean its pumping some would that help narrow down my problem??

brad8266

iTrader: (23)

pop the valve cover and crank it and see if oil comes out up there, indicating pressure.

blackbyrd

iTrader: (14)

heads are still try its got breathers so we have been looking also pulled the oil sender and poured oil down it but havent cranked it since doing that, needed a few things

The Alchemist

iTrader: (19)

Check the oil pressure sending unit that is in the back of the block I beleive. A lot of people hit it by accident when doing intake swaps. It will show 0 oil pressure because it's not sending any signal since it is an electronic gauge.

blackbyrd

iTrader: (14)

i already pulled the sendor and it was dry on the bottom oil is not coming up but yet its over filling the filter which i thought was the last place that it went?

also strange even tried cranking it with the sendor out and couldnt even feel air move which it should right? the more and more i think about this its sounding like the pick up tube is stuck on the bottom of the pan

speedracer5532

iTrader: (8)

The first place the oil goes from the pump is the oil filter.

blackbyrd

iTrader: (14)

if the 2 plugs were missing would it have filled the filter??

racecar

If the freeze plug is missing in the front of the block, the oil will just pump right back into the pan, 0 pressure. If the barbell is missing, IMO you should have pressure, it will bypass the filter. I have never tried that, but the barbell just sends oil down to the filter, and back up. If the pickup is touching the bottom of the pan, 0 pressure.
If everything is working, and you crank with the spark plugs out, it will make pressure in about 3 seconds. I agree with speedracer, it's usually the O ring.

blackbyrd

iTrader: (14)

so if it over filled the oil filter the rear plug is probably in

racecar

Some oil in the filter? We need more. Pull the front cover and pan, look for the freeze plug, buy a new O ring, check it all out before you toast those bearings. You can see the freeze plug in this photo, just to the right of the gold oil pump bolts.

ShevrolayZ28

iTrader: (4)

I wasn't able to get oil up to the rockers by turning it over with the starter (spark plugs out) and I've seen plenty of threads where people have had the same experience, yet once the car in question was fired, there was no problem- bingo! Oil pressure.

I think we need the crank shaft sloshing the oil around and a lot more RPM through the oil pump before we'll see anything happen. Also, if you're going by the OEM gage, none of the gages function while turning the starter.

I'd start it up and watch for pressure within the first few seconds; be ready to shut it down. If it's been sitting and it's not lubed with assembly juice and you're paranoid, pop off the valve cover and squirt some oil around inside.