Mgg4591

iTrader: (3)

Hello everyone. Ive been a member on TGO for a few years, and recently started a 5.3/t56 swap in my 86 sport coupe camaro. Ive been reading through countless oil pressure threads the past two days, but everything i try doesn't seem to work. Heres whats going on…

Engine is a 5.3 LM7, has 87k came out of a silverado. Bought it as a long block, the bottom end hasn't been torn down. I replaced the oil pump, timing chain, and did new gaskets on the whole motor before dropping it in. Got the motor in the car and everything wired up, just waiting for the PCM to get here.

Using a mechanical gauge, cranking the motor with the plugs out, i can't get any oil pressure. Pulled the oil filter, not a drop comes out while cranking either. I didn't pack the pump with vaseline before installation, or dip it in oil, so I'm leaning towards this being the issue. Im 90% sure the o ring isn't pinched, as it slid right up into place, and i supported the pickup as i tightened the bolt. I also placed the o-ring on the pickup tube, not in the pump, and didn't slide it all the way to the bottom, stopped it right before the bottom lip.

Also tried adding an extra quart of oil, and jacked the rear up nice and high while cranking, still nothing from the filter. I also checked before putting the front cover on, and the plug next to the pump was installed. Not sure what to do next. Is there anything else i can do to try to prime the pump, or do you think its not a priming issue? I read that some people say to just start it and it will build pressure, but the fact that I'm getting absolutely nothing from the filter input tells me not to start it.

JRENIGAR

iTrader: (37)

I dont think a non primed oil pump will build pressure with just cranking rpm's. If it were already primed then it should build some pressure while just cranking over. I wouldnt keep just cranking on it to see pressure or you will cause problems though. Get it ready to start then see if it builds pressure within 10 sec or so when fired up. IDK if it would work but you might be able to take off the oil pressuer unit and partially fill it through that small port on the top of the block behind the mani. Just a thought...

ss performance

iTrader: (17)

Check the oil pickup & pump.

The pump could be sucking air if the pickup isn't properly seated or the pickup could be to close to the oil pan. A friend could only get 10 psi checked the clearance from the pickup to the pan. The pickup was touching the pan.

Good luck.

Mgg4591

iTrader: (3)

I actually tried that this morning, but it didn't work. If i had just assembled it with lube and everything, i would just start it right up and watch the gauge. Engine was sitting in a garage for almost two years, so i really want to get pressure on that gauge before startup. Guess ill just have to drop the k member and pan again.

JRENIGAR

iTrader: (37)

If you could rig up a fitting comming from that port to the bottom of a container filled with oil and attach an adjustable air pressure source on the top side it would push oil through the bearings down to the pickup tube I would think. This would atleast assure there was oil in the bearings and you could go from there.

Mgg4591

iTrader: (3)

Im not going to be able to get to the garage till monday night to really try anything, but i think ill just pull the pan. Ill be able to double check the pickup o ring, and ill have a friend crank it while i check for suction from the pickup. If no suction, ill just stuff the bottom of the oil pump with vaseline and see what happens. Was reading a few threads this afternoon where that did the trick for a few people. I haven't put the exhaust or the brake lines back on, so it won't be too bad to drop the k member again.

Mike_hawk

I had the same problem when firing up my engine for the first time. I installed a new pump and new gauges and thought maybe the gauge was malfunctioning since it showed 00 while cranking. But I knew I had oil and that everything was installed correctly so I just fired it up, got 40 psi within a couple seconds. I have heard of people using the oil cooler lines to prime the system using compressed air.

Mgg4591

iTrader: (3)

I didn't try with compressed air, but i used a transfer pump and tried pumping oil through the input hole on the oil filter and back into the pump. Unfortunately that didn't do anything either, but i couldn't really get a good seal, and it wasn't pressurized, so i doubt the oil even made it to the pump. If i could get flow into the filter, then i would just start it. Held the key down for a good 15 seconds twice, then a bunch of 5 second cranks in between whenever i would try something else, but still nothing. I would think that if the o ring was pinched, i would at least get a tiny bit of oil into the filter, but i can't even get a drop.

The two main things I've been reading though has been a few members had pinched o rings and no flow to the filter, and a few guys pulled the pan and stuffed the pump with vaseline, and that got the oil to flow.

The only other thing i heard of and haven't tried yet was to remove the alternator and pump oil into that gallery plug behind it.. Not sure if it needs to be pressurized though to make it into the pump, or if i could just use a regular HF transfer pump.

Mgg4591

iTrader: (3)

Think I'm gonna shoot out to HF tomorrow night and give this a try.https://ls1tech.com/forums/tools-fab...nder-20-a.html

At least the bearings will be well oiled, might just go for the startup then and see what happens.

ZQ8LS1

iTrader: (3)

Did you install the "barbell" thing at the rear of the block ???

Mgg4591

iTrader: (3)

Never pulled it out, cant get any oil flow before the barbell.

jamesgr81

Oil pump pressure relief valve rusted/stuck open.

RonSSNova

iTrader: (3)

If you can get to the plug on the side near the alt and pump oil in there, it leads directly to the pump and should get it primed. You could even use a funnel and a hose.
I'd also fill the oil filter before installing it. If the o-ring slid in nice, it's not the problem.
Mine built 15psi on the starter, and I had used assembly lube on the pump gears. Took 20 seconds or so.

Good luck!

Ron

Mgg4591

iTrader: (3)

Thanks, im gonna go to harbor freight tonight and pick up a drill pump. Gonna pump oil throught the filter outlet and into the bearings, then pull that plug behind the alternator and pump it into there. Hope that does the trick.

jrpimp00

iTrader: (17)

Do you have the original oil cooler bypass installed and not blocked? Above the oil filter

Mgg4591

iTrader: (3)

Yea, have a bypass plate installed, cane with the oil pan. Pulled that plate too and its bone dry. Picked up the hf pump and the pcm came in today as well.
Ill get to fire it up for the first time and see if pressure builds monday night.

N20zuki

You don't want to pack these pumps with any type of grease, How long have you cranked the motor for while waiting on pressure? Why didn't you fill the oil filter up prior to installing it on the motor?

They sell a tool that's 200$ to prime these motors so I don't know how well just trying to spin it with the starter will work. These motors are not the same as is predecessors that spinning it over will prime the system as quickly.

And lastly did you lube the O-ring with oil and take a lot of care when aligning the pickup tube to the oil pump? It could of been pinched in the process.

Mgg4591

iTrader: (3)

I did fill up the filter, and have a mechanical pressure gauge hooked up. Spun with the starter a bunch of times. Held it down for 15 seconds twice, and a few 5 second runs. Can get anything into the filter at all like i said above.

Mgg4591

iTrader: (3)

Almost was able to start it tonight. Pumped some oil through the oil filter port and the gauge showed pressure. Couldn't find a couple AN fittings i ordered so i wasn't able to hook up the fuel and start it up to check for pressure. I know i have pressure after the filter now, so Im hoping once its started the pump will be able to prime itself. Ill know tomorrow night.

cantfind2nd

iTrader: (24)

make sure this plug is there.