New Cast Iron Oil Pump pressure low

[JimT]

Quick update regarding my newer oil pump. After nearly 10 months and 4 or 5 oil changes I can say this:

Pump/gear noise is loudest/most apparent with fresh oil (10 gallons Delo 15w40 + 1 gal Supertech 80w90). Noise is loudest when standing directly in front of truck or behind the truck.

After about 1,000-2,000 miles the noise fades into the background. Typically not noticeably louder than anything else, but still present if you know what to listen for. Also slightly louder when cold compared to hot.

Oil pressures are extremely consistent. 25 psi at hot idle (720 rpm) and 36 psi hot around 1600 rpm. When cold, even during this past winter, the pressure is usually only max about 7-8 psi higher than it would be when hot.

Oil pressure over the course of 15,000 miles varies only about 1 psi. The old oil just before a change was reading only about 1psi less then fresh oil.

All-in-all the pump I received, while a bit noisy, has been exceedingly consistent in operational performance.