2005 5.3 vortec top in no oil pres just got truck good moter or bad moter

Oil light usually indicates LOW oil pressure.. Which will kill your engi ne and cause very expense repairs. FIRST Check oil level, If the level is good. You need to find out if the engine really has low oil pressure. A new oil pressure switch is about $8.00 you might start there. If the light still comes on its a good posibilty your car has bad oil pres.. To find out for sure you will need to install a Pressure guage and check the actual pressure.. If the Oil Level is good and you still have low oil pressure The engine has internal wear or damage.. You should not drive it till you fix the low pressure problem. rebuild or replace engine. The intermittant "jerking" can be unrelated to the oil pres problem or you engine is going away because of the pressure problem.

That could be correct, or 180 degrees off. Top dead center on the crank shaft can be on the intake or exhaust stroke.

Check the cylinders and make sure they are good

If its the vortec engine everything is under the plastic intake on top of moter.they have plastic tubes under there which are called popet valves. Don't want to break them.they can make the moter black smoke and run bad if cracked.

REPLACE IT IF THAT DOESN'T WORK CHANGE FRONT MAIN SEAL

Its in the rear/ top /center. Hidden alittle, you can get it out with a special socket and it's not hard to access.

It could be lifters but its more likely that your not getting oil to the top right away. Probably plugged oil passages in the cylinder head. Remove the valve covers and clean it out. Change your oil and see if it helps. The damage may alreay be done though

the oil sending unit is bad

could be the oil sending unit

Hello, it seems that you have intake gaskets leaking. I'll bet you have the vortec 350. This is a common problem with the vortec, Gm uses plastic intake gaskets and they blow out over time usually to the externally but yours is internally.It is a pretty easy fix for the average mechanic to do. Thank you