tahoe no oil pressure

[tneels]

I have a2013 chevy tahoe with a5.3ls motor. Blew the engine so I bought a used one online with a warranty. We put a new oil pan without the relief valve in it. New oil filter, new pick up tube with o ring, new high volume oil pump new screen and oil pressure sensor and new vlom. Wet hooked up a manual Guage where the pressure sensor goes and still no oil pressure to the top of the motor . Took the Guage back off and oil shoots out of where the Guage goes. So hooked the Guage back up and still no oil pressure. Decided to start it up and no oil pressure until I revved it up to 3000rpm then oil pressure went to 20 let off the gas and the pressure dropped to zero. I am in desperate need of what to do we are also running 5w30 thought of maybe using a thicker oil. Idk I am stumped have alot of money invested and have been stumped working on this issue for 3 months now I need any help I can get Thanks

 

[Tahoe14]

Does the salvage yard offer replacements if there is a problem. Most reputable yards do.

 

[tneels]

Yes it has a warranty. Just gotta take it all back out and ship it back and wait to get another one. But it dies start and run can't hear any pinging or anything

 

[ls1frc]

Sounds like you pinched oil pump o ring

 

[Rocket Man]

Sounds like you pinched oil pump o ring

Or used the wrong o-ring. Or the motor is shot.

 

[ls1frc]

Well it's from a salvage yard, they're typically tested before they sell them. I have a junkyard motor in mine and oil PSI is great.

OP said he replaced oil pump, so I would bet the o-ring was pinched or the car version was used like you say.

 

[wsteele]

Or used the wrong o-ring. Or the motor is shot.

I would say about 90% chance of a new oil pump installation error.

 

[tneels]

I used the green o ring which is the right one and this is the high volume oil pump like i said if I Rev it up to 3000rpm it does go to 20psi but when I let off the accelerator it drops to 0

 

[wsteele]

I used the green o ring which is the right one and this is the high volume oil pump like i said if I Rev it up to 3000rpm it does go to 20psi but when I let off the accelerator it drops to 0

You might try the nose down on an incline and overfill with oil test, to rule out a bad/pinched O ring. You just put a couple extra qts in after parking it nose down on a pretty steep driveway. The oil in the pan will cover that fitting and eliminate you sucking oil through a bad o ring. If pressure still doesn’t go up, you know it isn’t the o ring.

 

[Rocket Man]

You might try the nose down on an incline and overfill with oil test, to rule out a bad/pinched O ring. You just put a couple extra qts in after parking it nose down on a pretty steep driveway. The oil in the pan will cover that fitting and eliminate you sucking oil through a bad o ring. If pressure still doesn’t go up, you know it isn’t the o ring.

Great idea .