Original oil pressure specs

[Mike GMC]

Does anyone know what the original oil pressure specs are for a 2000 5.3? I know my pressure is a bit lower than it used to be, but I don't know what it's supposed to be. I bought the truck used a few years ago.

 

Thanks.

[muddkatt]

My 01 has 40psi at idle and about 60psi at 55mph when the engine is at operating temperature. Truck has held the same pressures since new, 314000 miles on her now.

[Mike GMC]

That's about where mine used to run. Now I see about 30 at idle and 40 ish at highway speed. If I stand on it and Rev it up I get close to 60. This is with new oil. It drops a little more on old oil.

[muddkatt]

Sounds like a little wear on the bearings, or maybe a sending unit is not at peak performance....just drive it. Those pressures are fine.

[Mike GMC]

Sending unit is new. The old one was leaking. Just to see if I could trust the dash gauge, I installed a mechanical gauge using the oil cooler port cover. The mechanical matches the dash pretty closely. The biggest difference is just how fast they move. The mechanical is much slower and smoother. The dash gauge gets "jittery" sometimes. Now that I know I can trust the dash gauge, at least mostly, I will be removing the mechandical gauge.

 

It's hard to tell if it's just bearing wear or if the pump might be failing, or maybe even a clogged pickup.