Before I get the usual, "just do a search"...I did. I'm at a loss for options. I need a second set of eyes per-say. Here is the deal.

Stock bottom end 6 liter. ZERO oil pressure, not even a little bit, even after priming the pump, and cranking without coil packs plugged in.

-New GM LS6 oil pump
-Barbell is installed correctly in the rear
-O-ring is new at the pump
-I used an LS pick-up, and pan (clearance shouldn't be an issue).
-Bypass valve in the pump is closed
-Pulled the front cover off. Pulled the plate off the pump, its full of oil.
-Pulled the valve cover on the drivers side, bone dry.

What is left to look at? I'm stuck and frustrated!

 

Hmmm, does a cranking a motor over even generate enough rpm to register on the guage? My oil guage does even register for like a half second once the car is started.

 

I just re-read your post & assume you're using an ls1 style pick-up tube.. The truck 6.0's use a different pan & pick-up tube, not sure if it's the cause for your issue, might look into it though.

-Mike

 

How long did you crank it with no coils. You can remove spark plugs to make turning the motor easier and faster.

Is your oil pressure gauge good?
Try filling the oil filter with oil then put it back.
Check your o-ring, it could be punched during install.
Prime it again.

Last, it could be your pump. You may try another pump.

 

I assume the gauge is good. Its a brand new Autometer gauge.
Cranked with no coils for probably 30 seconds. I always fill the filter with oil before I put it back on.

I'm getting ready to change to another pump. This is becoming a real pain in the ***.

 

Its an LS1 pan and an LS1 pick up tube.

 

I did the Melling 296 pump (which I recommend), and just cranked a couple revolutions to make sure the valves weren't hitting the pistons. Connected the coils, and turned the key. Started immediately, and had good oil pressure in less than a second. I say check the oil level, and fire it up. Wait 3 seconds and shut it off if no pressure.....

 

Thats what I'm debating on doing. I'm getting oil to the pump, just nothing to the gauge sensor. I'm just wondering if I'm not giving it enough time to circulate. Then again, if there is a problem, I'm gonna screw up the motor and have to pull it out.

I don't know what to do.

 

My advise not to start it until you make sure your pump delivers pressure while cranking. You will damage your bearings in less than 3 seconds.

I am saying that because I did that mistake, trust me.

 

I just packed the pump with Vasoline and cranked it with the starter for about 15 seconds. My gauges are hooked up to switched power, so I cant tell if there is any pressure during crank. I went ahead and took off the valve cover and the head was still bone dry. I'm guessing I try pump number two. I'm pretty much at a loss right now.

 

It is not the pump...unless it is broken it will pump oil...either the pickup tube is incorrectly installed (o ring not sealing) or else you left out one of the oil galley plugs or the dumbell. Everyone blames the pump and 99 percent of the time it is assembly mistakes. It is very easy to build oil pressure in these engines...I leave the plugs out so it spins real easy and you get oil pressure in a hurry...spinning a few seconds and letting it set for a while also helps get air out of system as does the jelly packing...I am not sure I like pumping the jelly to the bearings but it probably does not hurt anything.

 

I've exhausted every option except changing the oil pump. It has to come off to check the o-ring anyway.

 

did u remove cam plate? if the bolts are loose it will cause a problem...thats the last place it builds oil pressure from what i understand.... hope it helps

 

i forgot what they are called but there is a seal that looks like a "barbell that is in the front and rear of the motor. if they are not there you will have zero oil pressure.

 

Thats only in the rear i believe....

 

No. Cam end plates. Front behind timing chain.

 

my buddy had the same problem it would not register any oil pressure until he started the car because it drew all the power to turn it over. but when he hooked everything up and started it had plenty of pressure

 

I just got the same problem, fresh built 383 had great oil pressure around 60psi cold then after about 20 mins of driving and one squirt to 4000rpm the oil warnings came on so I switched it off and rolled it home. Screwed in a manual pressure gauge and no oil pressure what so ever now. Pulled the timing cover to see if it had a broken pump, pump is perfect, pickup is still in place, releif valve is closed, no idea what it could be so I guess tonight its off with the sump.
Any ideas?

 

If you question the pump, just replace it. It is cheaper and easier that a crank and bearings.

 

Did you install a timing set? Did it require shimming the pump?

It takes time to prime the pump. Did you try enough?