ok guys make along story short, i change out the short block in my car and now when i crank the car it has no oil pressure, but soon as i hit the gas it will shoot up and start makeing pressure,So i when back in to it and put a new o ring on the pick up tube and it DIDNT fix my problem, its still doing the same thing, at idle it will hold maybe 10lbs of pressure. soon as i hit the gas it will shoot up help!!!

 

what kind of oil, what kind of filter, what block, what did you swap over, etc.

 

Assuming the new short block was built properly, this sounds like the oil pump's bypass plunger has stuck.

 

its a stock short block out of a 04 gto 5.7, 10/30 mobil one k/n oil filter

 

i did the swap, if the oil pulg is not in the back of the block would it cause this to happen? cant remmber if it was n there!

 

If the little barbell looking plug is missing you'll have oil pressure problems. But that usually happens with newly-built engines, no reason the junkyard would pull one from a takeout engine.

You've got good oil and an excellent filter, so they're not the issue.

Did you install a double-row timing set? Check for the extension blocks installed backwards if so.

If the barbell plug is in, and you're positive the O-ring was installed right:

1.) O-ring above the raised ridge on the pickup tube, not below it...
2.) O-ring on the pickup tube before you slid it into the pump, rather than installing the O-ring inside the pump and then sliding the pickup into place...

After these, you're left with either the oil pump failed or the engine was junk when you got it.

 

ok man thanks

 

Good luck! Let us know what you find.

 

ok,, im going to tear in to it on monday hope its missing a oil vally plug

 

ok guys i tore her down and the oil vally piug was not i n the back of the block, i pull one in it, and put the car back togeather, fired her up and that fix my problem,