No oil PSI after rebuild

[Andrew Reynolds]

I think I know the answer to this but wanted to pick everyone's brain as to what could possibly be wrong. I rebuild my Gen 3 6.0 and went to go prime the motor with the starter with the coils and injectors unplugged. It never built any oil pressure. Gauge never moved. I am using an autometer oil pressure gauge with a capillary tube so I thought maybe I kinked the line or since it was in the oil cooler adapter it needed some more oil. So I pulled my oil pressure sender up top and installed another oil pressure gauge I know works and again no pressure after 5 -10 revolutions of the motor. The batter was low though so it wasn't spinning full speed but all I could see in the tube was a few drops of oil. I am thinking the oil pump I got must be bad. I did buy it used and it was a mellings high volume pump. I shimmed it on install like mellings suggests. Just wanted to get some other opinions before i tore into it.

Thanks

 

[Supercharged111]

You won't see any pressure spinning it with the starter. At least I never did.

 

[RichLo]

This is cheap insurance after a rebuild. Pull the distributor, put this in there and attach it to a hand drill. Spin until you get oil coming out of all the rockers and check oil pressure.

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https://www.speedwaymotors.com/Mr-Gasket-3795G-Engine-Oil-Primer-Tool-Chevy-Pontiac,288096.html

 

[Jglew82]

This is cheap insurance after a rebuild. Pull the distributor, put this in there and attach it to a hand drill. Spin until you get oil coming out of all the rockers and check oil pressure.

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https://www.speedwaymotors.com/Mr-Gasket-3795G-Engine-Oil-Primer-Tool-Chevy-Pontiac,288096.html

This won't work for Gen 3's since they don't have distributors.

OP, your options are to pressure prime it through the large plug on the driver's side using special fittings and a pressurized oil tank, or bite the bullet and start it. I went through all this as well, and it came up to 45 psi as soon as it fired. As others have said, you probably won't see any pressure doing dry cranks.

 

[Supercharged111]

This is cheap insurance after a rebuild. Pull the distributor, put this in there and attach it to a hand drill. Spin until you get oil coming out of all the rockers and check oil pressure.

You must be registered for see images attach

https://www.speedwaymotors.com/Mr-Gasket-3795G-Engine-Oil-Primer-Tool-Chevy-Pontiac,288096.html

Even if it were a 350, that thing is junk. You need to style that plugs the distributor mounting area in order to get the lifters to flow.

 

[RichLo]

lol, oops. I must have looked past the 6.0 LS comment and I just picked the cheapest one for the OP since it seemed like it would be a one time use tool for him. My mistake, please ignore my previous comment.

 

[Andrew Reynolds]

Ok so I started it and boom right to 45#'s. I actually used the pressure pre-oiler first when I didnt see oil pressure the first time. I have an oil cooler on it though with 5/8 cooler hose so it was way to big to build pressure there unless running. Thanks for the help Guys!!!

 

[RDF1]

For future reference... you can hold the throttle to the floor for the PCM to enter "Flood Clear" mode. It disables the injectors from pulsing.

Also you need a hot battery to get the engine rpms high enough to flow some oil.

If you have engine assembly lube on everything and filled the oil filter up before install, along with a little assembly lube on the oil pump gears, It should built pressure within a couple seconds after firing up.


I got a call to go help a shop that was having issues with a L76 6.0 in a jeep buggy. No oil pressure. Ended up finding they made a plate and blocked off the oil port boss above the oil filter. As many times as they ran it without oil, I don't think your gonna hurt the bearings cranking it for 2 seconds before pressure built.

Sent from my HiDiNg PlAcE