I recently replaced the rod bearings and the oil pump on my 125k mile '95 z28 and occasionally as I'm slowing to a stop light, the oil pressure drops to 0psi, then when I tap the throttle, it jumps back up. It idles at 20-25psi when warm and 40psi when cold. While cruising its at 60psi cold and 40-45psi while warm. I've only noticed this momentary drop as I'm slowing to a stop light.

Also there is a slight hum coming from the bottom of the oil pan.

Could my new bearings be shot already? I didn't have the crank machined because the journals looked fine. I checked the oil and the level is fine and I'm running SAE 30 oil.

 

Sounds like a pick-up problem.

 

That would make sense, since it only happens while slowing down, but the pickup tube was installed on the new pump at the same angle as the old pickup was on the old pump. It was pretty tough to get in there and after I installed it, it wouldn't budge, so I'm sure it's still in place. I have to replace my oil level sensor, so I could take a peak in there to make sure it's still in place.

Is there somethin I could have overlooked that caused this issue?