crashmymax

iTrader: (1)

I had my engine rebuilt professionally but I am getting no oil pressure. I have hooked up a mechanical gauge to make sure. I also pre oiled the engine and was able to build pressure at the factory gauge so I doubt its a gauge issue. I also pulled the drain plug to check if the pickup tube is there and I'm fairly certain I can see it. Engine is 5.3 had it bored to 5.7 dod delete kit installed triple 12 cam rods pistons stock crank.

I have started it twice ran for a second or 2 then died. Since the attempted starts I have cranked it about 6 times after the mechanical gauge install but no pressure. engine has sat for about a year after rebuild do ls engines have trouble priming?

What should I start with to figure this out?

darkirish63

iTrader: (5)

If the motor has sat for a year, the o-ring on the pickup tube is probably rotted away. Best to drop the pan and check it out. If its shot it won't build pressure.

crashmymax

iTrader: (1)

It's worth a shot but I can't see an o ring rotting out in a year.

crashmymax

iTrader: (1)

O ring is in perfect condition. Can anyone confirm this mod? Plugging this hole I think it was a pressure relief valve or something. I want to make sure before reinstalling the pan. Anything else to be checked with pan off?

rennat_2006

iTrader: (10)

Yes that can be plugged after doi g a dod/afm delete. It is a relief valve from what ive found that limits oil pressure to around 55psi.

Is your oil filter full? That right there will take a few seconds to fill.
Did you plug the afm oil ports or use the correct valley cover with the orings to seal the ports?

Isnt there some barbell type deal that is common to be forgotten to be reinstalled that kills oil pressure?

RedXray

The most common low oil pressure issues are the pickup o-ring, missing barbell (posted above) and using an old cam thrust plate. If the old thrust plates orange gasket is squished flat oil pressure dumps from the lifter oil galleys into the front cover. This is usually a low pressure issue instead of a zero pressure issue. Check the oil filter like posted above and maybe pull a valve cover to see if the oil has actually made it to the top.

crashmymax

iTrader: (1)

The pickup tube oring looked fine but I replaced it any way. Still no oil pressure. I pre oiled the engine so it has oil at the valve covers. Does the engine have to be removed to get access to the barbell? Also replaced oil filter.

RedXray

The rear cover has to be removed to access the barbell. On my GenIII there is a oil plug on the drivers side block above the oil filter. You should be able to see the plastic barbell through this removed plug... but not install or remove the barbell.

RedXray

Are you sure you used the correct o-ring? There are two different ones depending on the type of pickup.

crashmymax

iTrader: (1)

I'll look for the oil plug and see what I can see. The pickup tube I removed had a green o ring. The new one I put in had a red o ring. It was a lot of work pulling the oil pan ended up removing the front diff and some other crap. Should have just pulled the engine.