Hi all, just bought a 2007 Sierra 2500hd 6.0 gas truck with ~230k miles on it.

When the truck is warm and idling, the low oil pressure alarm will start to chime and then go away once you accelerate. I know the common problem is the oil pressure sensor itself, or more likely the screen under it. The problem is I pulled mine and there was no screen. I'm guessing at this mileage it's possible I do actually have low oil pressure?

I've seen on another thread where sometimes it's just the o-ring between the oil pump and pickup tube that causes the low pressure.

 

have a shop test the oil pressure when its warm using a master gauge. this will tell you if the trucks gauge is accurate. if it is....maybe the oil pump is tired. maybe the bearing clearances are excessive.

 

What oil viscosity are you using? If verified low pressure as Tech says, you could try increasing viscosity. My 93 suburban with 350k does the same thing with 5-20. Using 20-50 gives me 10 more psi.

 

I probably should have diagnosed this further before tearing everything down, engine is already out of the truck. Here's a pic of the cam bearings, they look pretty worn. I need to pull the rod and main bearings still, and also see what the oil pump looks like.

 

if you are at that point take measurements/plasti-guage